freedom to copy and modify this GNU Manual, like GNU software. Copies
published by the Free Software Foundation raise funds for GNU
development.''
+@page
+This edition of the GDB manual is dedicated to the memory of Fred
+Fish. Fred was a long-standing contributor to GDB and to Free
+software in general. We will miss him.
@end titlepage
@page
Copyright (C) 1988-2006 Free Software Foundation, Inc.
+This edition of the GDB manual is dedicated to the memory of Fred
+Fish. Fred was a long-standing contributor to GDB and to Free
+software in general. We will miss him.
+
@menu
* Summary:: Summary of @value{GDBN}
* Sample Session:: A sample @value{GDBN} session
* Configurations:: Configuration-specific information
* Controlling GDB:: Controlling @value{GDBN}
* Sequences:: Canned sequences of commands
-* TUI:: @value{GDBN} Text User Interface
* Interpreters:: Command Interpreters
+* TUI:: @value{GDBN} Text User Interface
* Emacs:: Using @value{GDBN} under @sc{gnu} Emacs
-* Annotations:: @value{GDBN}'s annotation interface.
* GDB/MI:: @value{GDBN}'s Machine Interface.
+* Annotations:: @value{GDBN}'s annotation interface.
* GDB Bugs:: Reporting bugs in @value{GDBN}
-* Formatting Documentation:: How to format and print @value{GDBN} documentation
* Command Line Editing:: Command Line Editing
* Using History Interactively:: Using History Interactively
+* Formatting Documentation:: How to format and print @value{GDBN} documentation
* Installing GDB:: Installing GDB
* Maintenance Commands:: Maintenance Commands
* Remote Protocol:: GDB Remote Serial Protocol
* Agent Expressions:: The GDB Agent Expression Mechanism
+* Target Descriptions:: How targets can describe themselves to
+ @value{GDBN}
* Copying:: GNU General Public License says
how you can copy and share GDB
* GNU Free Documentation License:: The license for this documentation
@end itemize
You can use @value{GDBN} to debug programs written in C and C@t{++}.
-For more information, see @ref{Supported languages,,Supported languages}.
+For more information, see @ref{Supported Languages,,Supported Languages}.
For more information, see @ref{C,,C and C++}.
@cindex Modula-2
@end menu
@node Free Software
-@unnumberedsec Free software
+@unnumberedsec Free Software
@value{GDBN} is @dfn{free software}, protected by the @sc{gnu}
General Public License
frame IDs, independent frame sniffers, and the sentinel frame. Mark
Kettenis implemented the @sc{dwarf 2} unwinder, Jeff Johnston the
libunwind unwinder, and Andrew Cagney the dummy, sentinel, tramp, and
-trad unwinders. The architecture specific changes, each involving a
+trad unwinders. The architecture-specific changes, each involving a
complete rewrite of the architecture's frame code, were carried out by
Jim Blandy, Joel Brobecker, Kevin Buettner, Andrew Cagney, Stephane
Carrez, Randolph Chung, Orjan Friberg, Richard Henderson, Daniel
Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich
Weigand.
+Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from
+Tensilica, Inc.@: contributed support for Xtensa processors. Others
+who have worked on the Xtensa port of @value{GDBN} in the past include
+Steve Tjiang, John Newlin, and Scott Foehner.
+
@node Sample Session
@chapter A Sample @value{GDBN} Session
@b{define(baz,defn(<QUOTE>foo<UNQUOTE>))}
@b{baz}
-@b{C-d}
+@b{Ctrl-d}
m4: End of input: 0: fatal error: EOF in string
@end smallexample
lengths. We allow @code{m4} exit by giving it an EOF as input:
@smallexample
-@b{C-d}
+@b{Ctrl-d}
Program exited normally.
@end smallexample
@item
type @samp{@value{GDBP}} to start @value{GDBN}.
@item
-type @kbd{quit} or @kbd{C-d} to exit.
+type @kbd{quit} or @kbd{Ctrl-d} to exit.
@end itemize
@menu
* Invoking GDB:: How to start @value{GDBN}
* Quitting GDB:: How to quit @value{GDBN}
* Shell Commands:: How to use shell commands inside @value{GDBN}
-* Logging output:: How to log @value{GDBN}'s output to a file
+* Logging Output:: How to log @value{GDBN}'s output to a file
@end menu
@node Invoking GDB
executable file to the inferior using @code{--args}. This option stops
option processing.
@smallexample
-gdb --args gcc -O2 -c foo.c
+@value{GDBP} --args gcc -O2 -c foo.c
@end smallexample
This will cause @code{@value{GDBP}} to debug @code{gcc}, and to set
@code{gcc}'s command-line arguments (@pxref{Arguments}) to @samp{-O2 -c foo.c}.
@end menu
@node File Options
-@subsection Choosing files
+@subsection Choosing Files
When @value{GDBN} starts, it reads any arguments other than options as
specifying an executable file and core file (or process ID). This is
the same as if the arguments were specified by the @samp{-se} and
-@samp{-c} (or @samp{-p} options respectively. (@value{GDBN} reads the
+@samp{-c} (or @samp{-p}) options respectively. (@value{GDBN} reads the
first argument that does not have an associated option flag as
equivalent to the @samp{-se} option followed by that argument; and the
second argument that does not have an associated option flag, if any, as
@end table
@node Mode Options
-@subsection Choosing modes
+@subsection Choosing Modes
You can run @value{GDBN} in various alternative modes---for example, in
batch mode or quiet mode.
Do not execute commands found in any initialization files. Normally,
@value{GDBN} executes the commands in these files after all the command
options and arguments have been processed. @xref{Command Files,,Command
-files}.
+Files}.
@item -quiet
@itemx -silent
source, assembly, registers and @value{GDBN} command outputs
(@pxref{TUI, ,@value{GDBN} Text User Interface}). Alternatively, the
Text User Interface can be enabled by invoking the program
-@samp{gdbtui}. Do not use this option if you run @value{GDBN} from
+@samp{@value{GDBTUI}}. Do not use this option if you run @value{GDBN} from
Emacs (@pxref{Emacs, ,Using @value{GDBN} under @sc{gnu} Emacs}).
@c @item -xdb
@end table
@node Startup
-@subsection What @value{GDBN} does during startup
+@subsection What @value{GDBN} Does During Startup
@cindex @value{GDBN} startup
Here's the description of what @value{GDBN} does during session startup:
file in your home directory can set options (such as @samp{set
complaints}) that affect subsequent processing of command line options
and operands. Init files are not executed if you use the @samp{-nx}
-option (@pxref{Mode Options, ,Choosing modes}).
+option (@pxref{Mode Options, ,Choosing Modes}).
@cindex init file name
@cindex @file{.gdbinit}
-The @value{GDBN} init files are normally called @file{.gdbinit}.
-On some configurations of @value{GDBN}, the init file is known by a
-different name (these are typically environments where a specialized
-form of @value{GDBN} may need to coexist with other forms, hence a
-different name for the specialized version's init file). These are the
-environments with special init file names:
-
-@itemize @bullet
@cindex @file{gdb.ini}
-@item
+The @value{GDBN} init files are normally called @file{.gdbinit}.
The DJGPP port of @value{GDBN} uses the name @file{gdb.ini}, due to
the limitations of file names imposed by DOS filesystems. The Windows
ports of @value{GDBN} use the standard name, but if they find a
@file{gdb.ini} file, they warn you about that and suggest to rename
the file to the standard name.
-@cindex @file{.vxgdbinit}
-@item
-VxWorks (Wind River Systems real-time OS): @file{.vxgdbinit}
-
-@cindex @file{.os68gdbinit}
-@item
-OS68K (Enea Data Systems real-time OS): @file{.os68gdbinit}
-
-@cindex @file{.esgdbinit}
-@item
-ES-1800 (Ericsson Telecom AB M68000 emulator): @file{.esgdbinit}
-
-@item
-CISCO 68k: @file{.cisco-gdbinit}
-@end itemize
-
@node Quitting GDB
@section Quitting @value{GDBN}
@item quit @r{[}@var{expression}@r{]}
@itemx q
To exit @value{GDBN}, use the @code{quit} command (abbreviated
-@code{q}), or type an end-of-file character (usually @kbd{C-d}). If you
+@code{q}), or type an end-of-file character (usually @kbd{Ctrl-d}). If you
do not supply @var{expression}, @value{GDBN} will terminate normally;
otherwise it will terminate using the result of @var{expression} as the
error code.
@end table
@cindex interrupt
-An interrupt (often @kbd{C-c}) does not exit from @value{GDBN}, but rather
+An interrupt (often @kbd{Ctrl-c}) does not exit from @value{GDBN}, but rather
terminates the action of any @value{GDBN} command that is in progress and
returns to @value{GDBN} command level. It is safe to type the interrupt
character at any time because @value{GDBN} does not allow it to take effect
If you have been using @value{GDBN} to control an attached process or
device, you can release it with the @code{detach} command
-(@pxref{Attach, ,Debugging an already-running process}).
+(@pxref{Attach, ,Debugging an Already-running Process}).
@node Shell Commands
-@section Shell commands
+@section Shell Commands
If you need to execute occasional shell commands during your
debugging session, there is no need to leave or suspend @value{GDBN}; you can
arguments. This is equivalent to @samp{shell make @var{make-args}}.
@end table
-@node Logging output
-@section Logging output
+@node Logging Output
+@section Logging Output
@cindex logging @value{GDBN} output
@cindex save @value{GDBN} output to a file
@end menu
@node Command Syntax
-@section Command syntax
+@section Command Syntax
A @value{GDBN} command is a single line of input. There is no limit on
how long it can be. It starts with a command name, which is followed by
@value{GDBN} can also use @key{RET} in another way: to partition lengthy
output, in a way similar to the common utility @code{more}
-(@pxref{Screen Size,,Screen size}). Since it is easy to press one
+(@pxref{Screen Size,,Screen Size}). Since it is easy to press one
@key{RET} too many in this situation, @value{GDBN} disables command
repetition after any command that generates this sort of display.
@cindex comment
Any text from a @kbd{#} to the end of the line is a comment; it does
nothing. This is useful mainly in command files (@pxref{Command
-Files,,Command files}).
+Files,,Command Files}).
@cindex repeating command sequences
-@kindex C-o @r{(operate-and-get-next)}
-The @kbd{C-o} binding is useful for repeating a complex sequence of
-commands. This command accepts the current line, like @kbd{RET}, and
+@kindex Ctrl-o @r{(operate-and-get-next)}
+The @kbd{Ctrl-o} binding is useful for repeating a complex sequence of
+commands. This command accepts the current line, like @key{RET}, and
then fetches the next line relative to the current line from the history
for editing.
@node Completion
-@section Command completion
+@section Command Completion
@cindex completion
@cindex word completion
you have not yet started typing the argument list when you ask for
completion on an overloaded symbol.
-For more information about overloaded functions, see @ref{C plus plus
-expressions, ,C@t{++} expressions}. You can use the command @code{set
+For more information about overloaded functions, see @ref{C Plus Plus
+Expressions, ,C@t{++} Expressions}. You can use the command @code{set
overload-resolution off} to disable overload resolution;
-see @ref{Debugging C plus plus, ,@value{GDBN} features for C@t{++}}.
+see @ref{Debugging C Plus Plus, ,@value{GDBN} Features for C@t{++}}.
@node Help
-@section Getting help
+@section Getting Help
@cindex online documentation
@kindex help
stack -- Examining the stack
status -- Status inquiries
support -- Support facilities
-tracepoints -- Tracing of program execution without@*
+tracepoints -- Tracing of program execution without
stopping the program
user-defined -- User-defined commands
@c Line break in "show" line falsifies real output, but needed
@c to fit in smallbook page size.
info -- Generic command for showing things
- about the program being debugged
+ about the program being debugged
show -- Generic command for showing things
- about the debugger
+ about the debugger
Type "help" followed by command name for full
documentation.
@smallexample
@c @group
set symbol-reloading -- Set dynamic symbol table reloading
- multiple times in one run
+ multiple times in one run
show symbol-reloading -- Show dynamic symbol table reloading
- multiple times in one run
+ multiple times in one run
@c @end group
@end smallexample
@end menu
@node Compilation
-@section Compiling for debugging
+@section Compiling for Debugging
In order to debug a program effectively, you need to generate
debugging information when you compile it. This debugging information
@need 2000
@node Starting
-@section Starting your program
+@section Starting your Program
@cindex starting
@cindex running
You must first specify the program name (except on VxWorks) with an
argument to @value{GDBN} (@pxref{Invocation, ,Getting In and Out of
@value{GDBN}}), or by using the @code{file} or @code{exec-file} command
-(@pxref{Files, ,Commands to specify files}).
+(@pxref{Files, ,Commands to Specify Files}).
@end table
the arguments.
In Unix systems, you can control which shell is used with the
@code{SHELL} environment variable.
-@xref{Arguments, ,Your program's arguments}.
+@xref{Arguments, ,Your Program's Arguments}.
@item The @emph{environment.}
Your program normally inherits its environment from @value{GDBN}, but you can
use the @value{GDBN} commands @code{set environment} and @code{unset
environment} to change parts of the environment that affect
-your program. @xref{Environment, ,Your program's environment}.
+your program. @xref{Environment, ,Your Program's Environment}.
@item The @emph{working directory.}
Your program inherits its working directory from @value{GDBN}. You can set
the @value{GDBN} working directory with the @code{cd} command in @value{GDBN}.
-@xref{Working Directory, ,Your program's working directory}.
+@xref{Working Directory, ,Your Program's Working Directory}.
@item The @emph{standard input and output.}
Your program normally uses the same device for standard input and
standard output as @value{GDBN} is using. You can redirect input and output
in the @code{run} command line, or you can use the @code{tty} command to
set a different device for your program.
-@xref{Input/Output, ,Your program's input and output}.
+@xref{Input/Output, ,Your Program's Input and Output}.
@cindex pipes
@emph{Warning:} While input and output redirection work, you cannot use
@end table
When you issue the @code{run} command, your program begins to execute
-immediately. @xref{Stopping, ,Stopping and continuing}, for discussion
+immediately. @xref{Stopping, ,Stopping and Continuing}, for discussion
of how to arrange for your program to stop. Once your program has
stopped, you may call functions in your program, using the @code{print}
or @code{call} commands. @xref{Data, ,Examining Data}.
@end table
@node Arguments
-@section Your program's arguments
+@section Your Program's Arguments
@cindex arguments (to your program)
The arguments to your program can be specified by the arguments of the
@end table
@node Environment
-@section Your program's environment
+@section Your Program's Environment
@cindex environment (of your program)
The @dfn{environment} consists of a set of environment variables and
@file{.profile}.
@node Working Directory
-@section Your program's working directory
+@section Your Program's Working Directory
@cindex working directory (of your program)
Each time you start your program with @code{run}, it inherits its
The @value{GDBN} working directory also serves as a default for the commands
that specify files for @value{GDBN} to operate on. @xref{Files, ,Commands to
-specify files}.
+Specify Files}.
@table @code
@kindex cd
current working directory of the debuggee.
@node Input/Output
-@section Your program's input and output
+@section Your Program's Input and Output
@cindex redirection
@cindex i/o
@end table
@node Attach
-@section Debugging an already-running process
+@section Debugging an Already-running Process
@kindex attach
@cindex attach
When you use @code{attach}, the debugger finds the program running in
the process first by looking in the current working directory, then (if
the program is not found) by using the source file search path
-(@pxref{Source Path, ,Specifying source directories}). You can also use
+(@pxref{Source Path, ,Specifying Source Directories}). You can also use
the @code{file} command to load the program. @xref{Files, ,Commands to
Specify Files}.
executing the command.
@end table
-If you exit @value{GDBN} or use the @code{run} command while you have an
-attached process, you kill that process. By default, @value{GDBN} asks
-for confirmation if you try to do either of these things; you can
-control whether or not you need to confirm by using the @code{set
-confirm} command (@pxref{Messages/Warnings, ,Optional warnings and
-messages}).
+If you exit @value{GDBN} while you have an attached process, you detach
+that process. If you use the @code{run} command, you kill that process.
+By default, @value{GDBN} asks for confirmation if you try to do either of these
+things; you can control whether or not you need to confirm by using the
+@code{set confirm} command (@pxref{Messages/Warnings, ,Optional Warnings and
+Messages}).
@node Kill Process
-@section Killing the child process
+@section Killing the Child Process
@table @code
@kindex kill
breakpoint settings).
@node Threads
-@section Debugging programs with multiple threads
+@section Debugging Programs with Multiple Threads
@cindex threads of execution
@cindex multiple threads
the target system's identification for the thread with a message in the
form @samp{[New @var{systag}]}. @var{systag} is a thread identifier
whose form varies depending on the particular system. For example, on
-LynxOS, you might see
+@sc{gnu}/Linux, you might see
@smallexample
-[New process 35 thread 27]
+[New Thread 46912507313328 (LWP 25582)]
@end smallexample
@noindent
message of the form @samp{[Switching to @var{systag}]} to identify the
thread.
-@xref{Thread Stops,,Stopping and starting multi-thread programs}, for
+@xref{Thread Stops,,Stopping and Starting Multi-thread Programs}, for
more information about how @value{GDBN} behaves when you stop and start
programs with multiple threads.
-@xref{Set Watchpoints,,Setting watchpoints}, for information about
+@xref{Set Watchpoints,,Setting Watchpoints}, for information about
watchpoints in programs with multiple threads.
@node Processes
-@section Debugging programs with multiple processes
+@section Debugging Programs with Multiple Processes
@cindex fork, debugging programs which call
@cindex multiple processes
@end table
To quit debugging one of the forked processes, you can either detach
-from it by using the @w{@code{detach-fork}} command (allowing it to
+from it by using the @w{@code{detach fork}} command (allowing it to
run independently), or delete (and kill) it using the
@w{@code{delete fork}} command.
@table @code
-@kindex detach-fork @var{fork-id}
-@item detach-fork @var{fork-id}
+@kindex detach fork @var{fork-id}
+@item detach fork @var{fork-id}
Detach from the process identified by @value{GDBN} fork number
@var{fork-id}, and remove it from the fork list. The process will be
allowed to run independently.
You can use the @code{catch} command to make @value{GDBN} stop whenever
a @code{fork}, @code{vfork}, or @code{exec} call is made. @xref{Set
-Catchpoints, ,Setting catchpoints}.
+Catchpoints, ,Setting Catchpoints}.
@node Checkpoint/Restart
-@section Setting a @emph{bookmark} to return to later
+@section Setting a @emph{Bookmark} to Return to Later
@cindex checkpoint
@cindex restart
If your program has saved a local copy of its process id, this could
potentially pose a problem.
-@subsection A non-obvious benefit of using checkpoints
+@subsection A Non-obvious Benefit of Using Checkpoints
On some systems such as @sc{gnu}/Linux, address space randomization
is performed on new processes for security reasons. This makes it
@end menu
@node Breakpoints
-@section Breakpoints, watchpoints, and catchpoints
+@section Breakpoints, Watchpoints, and Catchpoints
@cindex breakpoints
A @dfn{breakpoint} makes your program stop whenever a certain point in
the program is reached. For each breakpoint, you can add conditions to
control in finer detail whether your program stops. You can set
breakpoints with the @code{break} command and its variants (@pxref{Set
-Breaks, ,Setting breakpoints}), to specify the place where your program
+Breaks, ,Setting Breakpoints}), to specify the place where your program
should stop by line number, function name or exact address in the
program.
call).
@cindex watchpoints
+@cindex data breakpoints
@cindex memory tracing
@cindex breakpoint on memory address
@cindex breakpoint on variable modification
A @dfn{watchpoint} is a special breakpoint that stops your program
-when the value of an expression changes. You must use a different
-command to set watchpoints (@pxref{Set Watchpoints, ,Setting
-watchpoints}), but aside from that, you can manage a watchpoint like
-any other breakpoint: you enable, disable, and delete both breakpoints
-and watchpoints using the same commands.
+when the value of an expression changes. The expression may be a value
+of a variable, or it could involve values of one or more variables
+combined by operators, such as @samp{a + b}. This is sometimes called
+@dfn{data breakpoints}. You must use a different command to set
+watchpoints (@pxref{Set Watchpoints, ,Setting Watchpoints}), but aside
+from that, you can manage a watchpoint like any other breakpoint: you
+enable, disable, and delete both breakpoints and watchpoints using the
+same commands.
You can arrange to have values from your program displayed automatically
whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,,
-Automatic display}.
+Automatic Display}.
@cindex catchpoints
@cindex breakpoint on events
when a certain kind of event occurs, such as the throwing of a C@t{++}
exception or the loading of a library. As with watchpoints, you use a
different command to set a catchpoint (@pxref{Set Catchpoints, ,Setting
-catchpoints}), but aside from that, you can manage a catchpoint like any
+Catchpoints}), but aside from that, you can manage a catchpoint like any
other breakpoint. (To stop when your program receives a signal, use the
@code{handle} command; see @ref{Signals, ,Signals}.)
operate. A breakpoint range is either a single breakpoint number, like
@samp{5}, or two such numbers, in increasing order, separated by a
hyphen, like @samp{5-7}. When a breakpoint range is given to a command,
-all breakpoint in that range are operated on.
+all breakpoints in that range are operated on.
@menu
* Set Breaks:: Setting breakpoints
* Break Commands:: Breakpoint command lists
* Breakpoint Menus:: Breakpoint menus
* Error in Breakpoints:: ``Cannot insert breakpoints''
-* Breakpoint related warnings:: ``Breakpoint address adjusted...''
+* Breakpoint-related Warnings:: ``Breakpoint address adjusted...''
@end menu
@node Set Breaks
-@subsection Setting breakpoints
+@subsection Setting Breakpoints
@c FIXME LMB what does GDB do if no code on line of breakpt?
@c consider in particular declaration with/without initialization.
Breakpoints are set with the @code{break} command (abbreviated
@code{b}). The debugger convenience variable @samp{$bpnum} records the
number of the breakpoint you've set most recently; see @ref{Convenience
-Vars,, Convenience variables}, for a discussion of what you can do with
+Vars,, Convenience Variables}, for a discussion of what you can do with
convenience variables.
You have several ways to say where the breakpoint should go.
Set a breakpoint at entry to function @var{function}.
When using source languages that permit overloading of symbols, such as
C@t{++}, @var{function} may refer to more than one possible place to break.
-@xref{Breakpoint Menus,,Breakpoint menus}, for a discussion of that situation.
+@xref{Breakpoint Menus,,Breakpoint Menus}, for a discussion of that situation.
@item break +@var{offset}
@itemx break -@var{offset}
value is nonzero---that is, if @var{cond} evaluates as true.
@samp{@dots{}} stands for one of the possible arguments described
above (or no argument) specifying where to break. @xref{Conditions,
-,Break conditions}, for more information on breakpoint conditions.
+,Break Conditions}, for more information on breakpoint conditions.
@kindex tbreak
@item tbreak @var{args}
Set a breakpoint enabled only for one stop. @var{args} are the
same as for the @code{break} command, and the breakpoint is set in the same
way, but the breakpoint is automatically deleted after the first time your
-program stops there. @xref{Disabling, ,Disabling breakpoints}.
+program stops there. @xref{Disabling, ,Disabling Breakpoints}.
@kindex hbreak
@cindex hardware breakpoints
example, on the DSU, only two data breakpoints can be set at a time, and
@value{GDBN} will reject this command if more than two are used. Delete
or disable unused hardware breakpoints before setting new ones
-(@pxref{Disabling, ,Disabling}). @xref{Conditions, ,Break conditions}.
+(@pxref{Disabling, ,Disabling Breakpoints}).
+@xref{Conditions, ,Break Conditions}.
For remote targets, you can restrict the number of hardware
breakpoints @value{GDBN} will use, see @ref{set remote
hardware-breakpoint-limit}.
the breakpoint is automatically deleted after the
first time your program stops there. Also, like the @code{hbreak}
command, the breakpoint requires hardware support and some target hardware
-may not have this support. @xref{Disabling, ,Disabling breakpoints}.
-See also @ref{Conditions, ,Break conditions}.
+may not have this support. @xref{Disabling, ,Disabling Breakpoints}.
+See also @ref{Conditions, ,Break Conditions}.
@kindex rbreak
@cindex regular expression
@itemx info break @r{[}@var{n}@r{]}
@itemx info watchpoints @r{[}@var{n}@r{]}
Print a table of all breakpoints, watchpoints, and catchpoints set and
-not deleted, with the following columns for each breakpoint:
+not deleted. Optional argument @var{n} means print information only
+about the specified breakpoint (or watchpoint or catchpoint). For
+each breakpoint, following columns are printed:
@table @emph
@item Breakpoint Numbers
number @var{n} as argument lists only that breakpoint. The
convenience variable @code{$_} and the default examining-address for
the @code{x} command are set to the address of the last breakpoint
-listed (@pxref{Memory, ,Examining memory}).
+listed (@pxref{Memory, ,Examining Memory}).
@noindent
@code{info break} displays a count of the number of times the breakpoint
@value{GDBN} allows you to set any number of breakpoints at the same place in
your program. There is nothing silly or meaningless about this. When
the breakpoints are conditional, this is even useful
-(@pxref{Conditions, ,Break conditions}).
+(@pxref{Conditions, ,Break Conditions}).
@cindex pending breakpoints
If a specified breakpoint location cannot be found, it may be due to the fact
occurred since the time the breakpoint was disabled and one or more
of these loads could resolve the location.
+@cindex automatic hardware breakpoints
+For some targets, @value{GDBN} can automatically decide if hardware or
+software breakpoints should be used, depending on whether the
+breakpoint address is read-only or read-write. This applies to
+breakpoints set with the @code{break} command as well as to internal
+breakpoints set by commands like @code{next} and @code{finish}. For
+breakpoints set with @code{hbreak}, @value{GDBN} will always use hardware
+breakpoints.
+
+You can control this automatic behaviour with the following commands::
+
+@kindex set breakpoint auto-hw
+@kindex show breakpoint auto-hw
+@table @code
+@item set breakpoint auto-hw on
+This is the default behavior. When @value{GDBN} sets a breakpoint, it
+will try to use the target memory map to decide if software or hardware
+breakpoint must be used.
+
+@item set breakpoint auto-hw off
+This indicates @value{GDBN} should not automatically select breakpoint
+type. If the target provides a memory map, @value{GDBN} will warn when
+trying to set software breakpoint at a read-only address.
+@end table
+
+
@cindex negative breakpoint numbers
@cindex internal @value{GDBN} breakpoints
@value{GDBN} itself sometimes sets breakpoints in your program for
@node Set Watchpoints
-@subsection Setting watchpoints
+@subsection Setting Watchpoints
@cindex setting watchpoints
You can use a watchpoint to stop execution whenever the value of an
expression changes, without having to predict a particular place where
-this may happen.
+this may happen. (This is sometimes called a @dfn{data breakpoint}.)
+The expression may be as simple as the value of a single variable, or
+as complex as many variables combined by operators. Examples include:
+
+@itemize @bullet
+@item
+A reference to the value of a single variable.
+
+@item
+An address cast to an appropriate data type. For example,
+@samp{*(int *)0x12345678} will watch a 4-byte region at the specified
+address (assuming an @code{int} occupies 4 bytes).
+
+@item
+An arbitrarily complex expression, such as @samp{a*b + c/d}. The
+expression can use any operators valid in the program's native
+language (@pxref{Languages}).
+@end itemize
@cindex software watchpoints
@cindex hardware watchpoints
@table @code
@kindex watch
@item watch @var{expr}
-Set a watchpoint for an expression. @value{GDBN} will break when @var{expr}
-is written into by the program and its value changes.
+Set a watchpoint for an expression. @value{GDBN} will break when the
+expression @var{expr} is written into by the program and its value
+changes. The simplest (and the most popular) use of this command is
+to watch the value of a single variable:
+
+@smallexample
+(@value{GDBP}) watch foo
+@end smallexample
@kindex rwatch
@item rwatch @var{expr}
Set a watchpoint that will break when @var{expr} is either read from
or written into by the program.
-@kindex info watchpoints
+@kindex info watchpoints @r{[}@var{n}@r{]}
@item info watchpoints
This command prints a list of watchpoints, breakpoints, and catchpoints;
it is the same as @code{info break} (@pxref{Set Breaks}).
the underlying system supports them. (Note that hardware-assisted
watchpoints that were set @emph{before} setting
@code{can-use-hw-watchpoints} to zero will still use the hardware
-mechanism of watching expressiion values.)
+mechanism of watching expression values.)
@table @code
@item set can-use-hw-watchpoints
@noindent
If this happens, delete or disable some of the watchpoints.
+Watching complex expressions that reference many variables can also
+exhaust the resources available for hardware-assisted watchpoints.
+That's because @value{GDBN} needs to watch every variable in the
+expression with separately allocated resources.
+
The SPARClite DSU will generate traps when a program accesses some data
or instruction address that is assigned to the debug registers. For the
data addresses, DSU facilitates the @code{watch} command. However the
@xref{set remote hardware-watchpoint-limit}.
@node Set Catchpoints
-@subsection Setting catchpoints
+@subsection Setting Catchpoints
@cindex catchpoints, setting
@cindex exception handlers
@cindex event handling
@item catch
The catching of a C@t{++} exception.
+@item exception
+@cindex Ada exception catching
+@cindex catch Ada exceptions
+An Ada exception being raised. If an exception name is specified
+at the end of the command (eg @code{catch exception Program_Error}),
+the debugger will stop only when this specific exception is raised.
+Otherwise, the debugger stops execution when any Ada exception is raised.
+
+@item exception unhandled
+An exception that was raised but is not handled by the program.
+
+@item assert
+A failed Ada assertion.
+
@item exec
@cindex break on fork/exec
A call to @code{exec}. This is currently only available for HP-UX.
@noindent
To make the debugger catch all exceptions before any stack
unwinding takes place, set a breakpoint on @code{__raise_exception}
-(@pxref{Breakpoints, ,Breakpoints; watchpoints; and exceptions}).
+(@pxref{Breakpoints, ,Breakpoints; Watchpoints; and Exceptions}).
-With a conditional breakpoint (@pxref{Conditions, ,Break conditions})
+With a conditional breakpoint (@pxref{Conditions, ,Break Conditions})
that depends on the value of @var{id}, you can stop your program when
a specific exception is raised. You can use multiple conditional
breakpoints to stop your program when any of a number of exceptions are
@node Delete Breaks
-@subsection Deleting breakpoints
+@subsection Deleting Breakpoints
@cindex clearing breakpoints, watchpoints, catchpoints
@cindex deleting breakpoints, watchpoints, catchpoints
@kindex clear
@item clear
Delete any breakpoints at the next instruction to be executed in the
-selected stack frame (@pxref{Selection, ,Selecting a frame}). When
+selected stack frame (@pxref{Selection, ,Selecting a Frame}). When
the innermost frame is selected, this is a good way to delete a
breakpoint where your program just stopped.
@end table
@node Disabling
-@subsection Disabling breakpoints
+@subsection Disabling Breakpoints
@cindex enable/disable a breakpoint
Rather than deleting a breakpoint, watchpoint, or catchpoint, you might
@c FIXME: I think the following ``Except for [...] @code{tbreak}'' is
@c confusing: tbreak is also initially enabled.
Except for a breakpoint set with @code{tbreak} (@pxref{Set Breaks,
-,Setting breakpoints}), breakpoints that you set are initially enabled;
+,Setting Breakpoints}), breakpoints that you set are initially enabled;
subsequently, they become disabled or enabled only when you use one of
the commands above. (The command @code{until} can set and delete a
breakpoint of its own, but it does not change the state of your other
breakpoints; see @ref{Continuing and Stepping, ,Continuing and
-stepping}.)
+Stepping}.)
@node Conditions
-@subsection Break conditions
+@subsection Break Conditions
@cindex conditional breakpoints
@cindex breakpoint conditions
breakpoint commands are usually more convenient and flexible than break
conditions for the
purpose of performing side effects when a breakpoint is reached
-(@pxref{Break Commands, ,Breakpoint command lists}).
+(@pxref{Break Commands, ,Breakpoint Command Lists}).
Break conditions can be specified when a breakpoint is set, by using
@samp{if} in the arguments to the @code{break} command. @xref{Set
-Breaks, ,Setting breakpoints}. They can also be changed at any time
+Breaks, ,Setting Breakpoints}. They can also be changed at any time
with the @code{condition} command.
You can also use the @code{if} keyword with the @code{watch} command.
When you use @code{continue} to resume execution of your program from a
breakpoint, you can specify an ignore count directly as an argument to
@code{continue}, rather than using @code{ignore}. @xref{Continuing and
-Stepping,,Continuing and stepping}.
+Stepping,,Continuing and Stepping}.
If a breakpoint has a positive ignore count and a condition, the
condition is not checked. Once the ignore count reaches zero,
You could achieve the effect of the ignore count with a condition such
as @w{@samp{$foo-- <= 0}} using a debugger convenience variable that
is decremented each time. @xref{Convenience Vars, ,Convenience
-variables}.
+Variables}.
@end table
Ignore counts apply to breakpoints, watchpoints, and catchpoints.
@node Break Commands
-@subsection Breakpoint command lists
+@subsection Breakpoint Command Lists
@cindex breakpoint commands
You can give any breakpoint (or watchpoint or catchpoint) a series of
The commands @code{echo}, @code{output}, and @code{printf} allow you to
print precisely controlled output, and are often useful in silent
-breakpoints. @xref{Output, ,Commands for controlled output}.
+breakpoints. @xref{Output, ,Commands for Controlled Output}.
For example, here is how you could use breakpoint commands to print the
value of @code{x} at entry to @code{foo} whenever @code{x} is positive.
@end smallexample
@node Breakpoint Menus
-@subsection Breakpoint menus
+@subsection Breakpoint Menus
@cindex overloading
@cindex symbol overloading
When this message is printed, you need to disable or remove some of the
hardware-assisted breakpoints and watchpoints, and then continue.
-@node Breakpoint related warnings
+@node Breakpoint-related Warnings
@subsection ``Breakpoint address adjusted...''
@cindex breakpoint address adjusted
frequently than expected.
@node Continuing and Stepping
-@section Continuing and stepping
+@section Continuing and Stepping
@cindex stepping
@cindex continuing
any breakpoints set at that address are bypassed. The optional argument
@var{ignore-count} allows you to specify a further number of times to
ignore a breakpoint at this location; its effect is like that of
-@code{ignore} (@pxref{Conditions, ,Break conditions}).
+@code{ignore} (@pxref{Conditions, ,Break Conditions}).
The argument @var{ignore-count} is meaningful only when your program
stopped due to a breakpoint. At other times, the argument to
@end table
To resume execution at a different place, you can use @code{return}
-(@pxref{Returning, ,Returning from a function}) to go back to the
+(@pxref{Returning, ,Returning from a Function}) to go back to the
calling function; or @code{jump} (@pxref{Jumping, ,Continuing at a
-different address}) to go to an arbitrary location in your program.
+Different Address}) to go to an arbitrary location in your program.
A typical technique for using stepping is to set a breakpoint
-(@pxref{Breakpoints, ,Breakpoints; watchpoints; and catchpoints}) at the
+(@pxref{Breakpoints, ,Breakpoints; Watchpoints; and Catchpoints}) at the
beginning of the function or the section of your program where a problem
is believed to lie, run your program until it stops at that breakpoint,
and then step through the suspect area, examining the variables that are
returns. Print the returned value (if any).
Contrast this with the @code{return} command (@pxref{Returning,
-,Returning from a function}).
+,Returning from a Function}).
@kindex until
@kindex u @r{(@code{until})}
Continue running your program until either the specified location is
reached, or the current stack frame returns. @var{location} is any of
the forms of argument acceptable to @code{break} (@pxref{Set Breaks,
-,Setting breakpoints}). This form of the command uses breakpoints, and
+,Setting Breakpoints}). This form of the command uses breakpoints, and
hence is quicker than @code{until} without an argument. The specified
location is actually reached only if it is in the current frame. This
implies that @code{until} can be used to skip over recursive function
invocations. For instance in the code below, if the current location is
line @code{96}, issuing @code{until 99} will execute the program up to
-line @code{99} in the same invocation of factorial, i.e. after the inner
+line @code{99} in the same invocation of factorial, i.e., after the inner
invocations have returned.
@smallexample
It is often useful to do @samp{display/i $pc} when stepping by machine
instructions. This makes @value{GDBN} automatically display the next
instruction to be executed, each time your program stops. @xref{Auto
-Display,, Automatic display}.
+Display,, Automatic Display}.
An argument is a repeat count, as in @code{step}.
A signal is an asynchronous event that can happen in a program. The
operating system defines the possible kinds of signals, and gives each
kind a name and a number. For example, in Unix @code{SIGINT} is the
-signal a program gets when you type an interrupt character (often @kbd{C-c});
+signal a program gets when you type an interrupt character (often @kbd{Ctrl-c});
@code{SIGSEGV} is the signal a program gets from referencing a place in
memory far away from all the areas in use; @code{SIGALRM} occurs when
the alarm clock timer goes off (which happens only if your program has
handle each one. You can use this to see the signal numbers of all
the defined types of signals.
+@item info signals @var{sig}
+Similar, but print information only about the specified signal number.
+
@code{info handle} is an alias for @code{info signals}.
@kindex handle
-@item handle @var{signal} @var{keywords}@dots{}
+@item handle @var{signal} @r{[}@var{keywords}@dots{}@r{]}
Change the way @value{GDBN} handles signal @var{signal}. @var{signal}
can be the number of a signal or its name (with or without the
@samp{SIG} at the beginning); a list of signal numbers of the form
@samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the
-known signals. The @var{keywords} say what change to make.
+known signals. Optional arguments @var{keywords}, described below,
+say what change to make.
@end table
@c @group
execution; but your program would probably terminate immediately as
a result of the fatal signal once it saw the signal. To prevent this,
you can continue with @samp{signal 0}. @xref{Signaling, ,Giving your
-program a signal}.
+Program a Signal}.
@node Thread Stops
-@section Stopping and starting multi-thread programs
+@section Stopping and Starting Multi-thread Programs
When your program has multiple threads (@pxref{Threads,, Debugging
-programs with multiple threads}), you can choose whether to set
+Programs with Multiple Threads}), you can choose whether to set
breakpoints on all threads, or on a particular thread.
@table @code
particular, whenever you ask @value{GDBN} for the value of a variable in
your program, the value is found in the selected frame. There are
special @value{GDBN} commands to select whichever frame you are
-interested in. @xref{Selection, ,Selecting a frame}.
+interested in. @xref{Selection, ,Selecting a Frame}.
When your program stops, @value{GDBN} automatically selects the
currently executing frame and describes it briefly, similar to the
-@code{frame} command (@pxref{Frame Info, ,Information about a frame}).
+@code{frame} command (@pxref{Frame Info, ,Information about a Frame}).
@menu
* Frames:: Stack frames
@end menu
@node Frames
-@section Stack frames
+@section Stack Frames
@cindex frame, definition
@cindex stack frame
@c underflow problems.
@cindex frameless execution
Some compilers provide a way to compile functions so that they operate
-without stack frames. (For example, the @value{GCC} option
+without stack frames. (For example, the @value{NGCC} option
@smallexample
@samp{-fomit-frame-pointer}
@end smallexample
frames in the stack.
You can stop the backtrace at any time by typing the system interrupt
-character, normally @kbd{C-c}.
+character, normally @kbd{Ctrl-c}.
@item backtrace @var{n}
@itemx bt @var{n}
Similar, but print only the outermost @var{n} frames.
@item backtrace full
-Print the values of the local variables also.
@itemx bt full
+@itemx bt full @var{n}
+@itemx bt full -@var{n}
+Print the values of the local variables also. @var{n} specifies the
+number of frames to print, as described above.
@end table
@kindex where
and is likely before the user entry point @code{main} (or equivalent) is called.
@item set backtrace past-entry off
-Backtraces will stop when they encouter the internal entry point of an
+Backtraces will stop when they encounter the internal entry point of an
application. This is the default.
@item show backtrace past-entry
@end table
@node Selection
-@section Selecting a frame
+@section Selecting a Frame
Most commands for examining the stack and other data in your program work on
whichever stack frame is selected at the moment. Here are the commands for
prints ten lines centered on the point of execution in the frame.
You can also edit the program at the point of execution with your favorite
editing program by typing @code{edit}.
-@xref{List, ,Printing source lines},
+@xref{List, ,Printing Source Lines},
for details.
@table @code
@end table
@node Frame Info
-@section Information about a frame
+@section Information About a Frame
There are several other commands to print information about the selected
stack frame.
frame is selected, but prints a brief description of the currently
selected stack frame. It can be abbreviated @code{f}. With an
argument, this command is used to select a stack frame.
-@xref{Selection, ,Selecting a frame}.
+@xref{Selection, ,Selecting a Frame}.
@kindex info frame
@kindex info f @r{(@code{info frame})}
selecting that frame. The selected frame remains unchanged by this
command. This requires the same kind of address (more than one for some
architectures) that you specify in the @code{frame} command.
-@xref{Selection, ,Selecting a frame}.
+@xref{Selection, ,Selecting a Frame}.
@kindex info args
@item info args
current stack frame at the current point of execution. To see other
exception handlers, visit the associated frame (using the @code{up},
@code{down}, or @code{frame} commands); then type @code{info catch}.
-@xref{Set Catchpoints, , Setting catchpoints}.
+@xref{Set Catchpoints, , Setting Catchpoints}.
@end table
information recorded in the program tells @value{GDBN} what source files were
used to build it. When your program stops, @value{GDBN} spontaneously prints
the line where it stopped. Likewise, when you select a stack frame
-(@pxref{Selection, ,Selecting a frame}), @value{GDBN} prints the line where
+(@pxref{Selection, ,Selecting a Frame}), @value{GDBN} prints the line where
execution in that frame has stopped. You can print other portions of
source files by explicit command.
@end menu
@node List
-@section Printing source lines
+@section Printing Source Lines
@kindex list
@kindex l @r{(@code{list})}
@end table
@node Edit
-@section Editing source files
+@section Editing Source Files
@cindex editing source files
@kindex edit
@var{address} may be any expression.
@end table
-@subsection Choosing your editor
+@subsection Choosing your Editor
You can customize @value{GDBN} to use any editor you want
@footnote{
The only restriction is that your editor (say @code{ex}), recognizes the
@end smallexample
@node Search
-@section Searching source files
+@section Searching Source Files
@cindex searching source files
There are two commands for searching through the current source file for a
@end table
@node Source Path
-@section Specifying source directories
+@section Specifying Source Directories
@cindex source path
@cindex directories for source files
The search path is used to find both program source files and @value{GDBN}
script files (read using the @samp{-command} option and @samp{source} command).
+In addition to the source path, @value{GDBN} provides a set of commands
+that manage a list of source path substitution rules. A @dfn{substitution
+rule} specifies how to rewrite source directories stored in the program's
+debug information in case the sources were moved to a different
+directory between compilation and debugging. A rule is made of
+two strings, the first specifying what needs to be rewritten in
+the path, and the second specifying how it should be rewritten.
+In @ref{set substitute-path}, we name these two parts @var{from} and
+@var{to} respectively. @value{GDBN} does a simple string replacement
+of @var{from} with @var{to} at the start of the directory part of the
+source file name, and uses that result instead of the original file
+name to look up the sources.
+
+Using the previous example, suppose the @file{foo-1.0} tree has been
+moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell
+@value{GDBN} to replace @file{/usr/src} in all source path names with
+@file{/mnt/cross}. The first lookup will then be
+@file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location
+of @file{/usr/src/foo-1.0/lib/foo.c}. To define a source path
+substitution rule, use the @code{set substitute-path} command
+(@pxref{set substitute-path}).
+
+To avoid unexpected substitution results, a rule is applied only if the
+@var{from} part of the directory name ends at a directory separator.
+For instance, a rule substituting @file{/usr/source} into
+@file{/mnt/cross} will be applied to @file{/usr/source/foo-1.0} but
+not to @file{/usr/sourceware/foo-2.0}. And because the substitution
+is applied only at the beginning of the directory name, this rule will
+not be applied to @file{/root/usr/source/baz.c} either.
+
+In many cases, you can achieve the same result using the @code{directory}
+command. However, @code{set substitute-path} can be more efficient in
+the case where the sources are organized in a complex tree with multiple
+subdirectories. With the @code{directory} command, you need to add each
+subdirectory of your project. If you moved the entire tree while
+preserving its internal organization, then @code{set substitute-path}
+allows you to direct the debugger to all the sources with one single
+command.
+
+@code{set substitute-path} is also more than just a shortcut command.
+The source path is only used if the file at the original location no
+longer exists. On the other hand, @code{set substitute-path} modifies
+the debugger behavior to look at the rewritten location instead. So, if
+for any reason a source file that is not relevant to your executable is
+located at the original location, a substitution rule is the only
+method available to point @value{GDBN} at the new location.
+
@table @code
@item directory @var{dirname} @dots{}
@item dir @var{dirname} @dots{}
@kindex cdir
@kindex cwd
@vindex $cdir@r{, convenience variable}
-@vindex $cwdr@r{, convenience variable}
+@vindex $cwd@r{, convenience variable}
@cindex compilation directory
@cindex current directory
@cindex working directory
@item show directories
@kindex show directories
Print the source path: show which directories it contains.
+
+@anchor{set substitute-path}
+@item set substitute-path @var{from} @var{to}
+@kindex set substitute-path
+Define a source path substitution rule, and add it at the end of the
+current list of existing substitution rules. If a rule with the same
+@var{from} was already defined, then the old rule is also deleted.
+
+For example, if the file @file{/foo/bar/baz.c} was moved to
+@file{/mnt/cross/baz.c}, then the command
+
+@smallexample
+(@value{GDBP}) set substitute-path /usr/src /mnt/cross
+@end smallexample
+
+@noindent
+will tell @value{GDBN} to replace @samp{/usr/src} with
+@samp{/mnt/cross}, which will allow @value{GDBN} to find the file
+@file{baz.c} even though it was moved.
+
+In the case when more than one substitution rule have been defined,
+the rules are evaluated one by one in the order where they have been
+defined. The first one matching, if any, is selected to perform
+the substitution.
+
+For instance, if we had entered the following commands:
+
+@smallexample
+(@value{GDBP}) set substitute-path /usr/src/include /mnt/include
+(@value{GDBP}) set substitute-path /usr/src /mnt/src
+@end smallexample
+
+@noindent
+@value{GDBN} would then rewrite @file{/usr/src/include/defs.h} into
+@file{/mnt/include/defs.h} by using the first rule. However, it would
+use the second rule to rewrite @file{/usr/src/lib/foo.c} into
+@file{/mnt/src/lib/foo.c}.
+
+
+@item unset substitute-path [path]
+@kindex unset substitute-path
+If a path is specified, search the current list of substitution rules
+for a rule that would rewrite that path. Delete that rule if found.
+A warning is emitted by the debugger if no rule could be found.
+
+If no path is specified, then all substitution rules are deleted.
+
+@item show substitute-path [path]
+@kindex show substitute-path
+If a path is specified, then print the source path substitution rule
+which would rewrite that path, if any.
+
+If no path is specified, then print all existing source path substitution
+rules.
+
@end table
If your source path is cluttered with directories that are no longer of
@end enumerate
@node Machine Code
-@section Source and machine code
+@section Source and Machine Code
@cindex source line and its code address
You can use the command @code{info line} to map source lines to program
Print the starting and ending addresses of the compiled code for
source line @var{linespec}. You can specify source lines in any of
the ways understood by the @code{list} command (@pxref{List, ,Printing
-source lines}).
+Source Lines}).
@end table
For example, we can use @code{info line} to discover the location of
After @code{info line}, the default address for the @code{x} command
is changed to the starting address of the line, so that @samp{x/i} is
sufficient to begin examining the machine code (@pxref{Memory,
-,Examining memory}). Also, this address is saved as the value of the
+,Examining Memory}). Also, this address is saved as the value of the
convenience variable @code{$_} (@pxref{Convenience Vars, ,Convenience
-variables}).
+Variables}).
@table @code
@kindex disassemble
value of @var{expr} is printed in a format appropriate to its data type;
you can choose a different format by specifying @samp{/@var{f}}, where
@var{f} is a letter specifying the format; see @ref{Output Formats,,Output
-formats}.
+Formats}.
@item print
@itemx print /@var{f}
@cindex reprint the last value
If you omit @var{expr}, @value{GDBN} displays the last value again (from the
-@dfn{value history}; @pxref{Value History, ,Value history}). This allows you to
+@dfn{value history}; @pxref{Value History, ,Value History}). This allows you to
conveniently inspect the same value in an alternative format.
@end table
A more low-level way of examining data is with the @code{x} command.
It examines data in memory at a specified address and prints it in a
-specified format. @xref{Memory, ,Examining memory}.
+specified format. @xref{Memory, ,Examining Memory}.
If you are interested in information about types, or about how the
fields of a struct or a class are declared, use the @code{ptype @var{exp}}
@table @code
@item @@
@samp{@@} is a binary operator for treating parts of memory as arrays.
-@xref{Arrays, ,Artificial arrays}, for more information.
+@xref{Arrays, ,Artificial Arrays}, for more information.
@item ::
@samp{::} allows you to specify a variable in terms of the file or
-function where it is defined. @xref{Variables, ,Program variables}.
+function where it is defined. @xref{Variables, ,Program Variables}.
@cindex @{@var{type}@}
@cindex type casting memory
@end table
@node Variables
-@section Program variables
+@section Program Variables
The most common kind of expression to use is the name of a variable
in your program.
Variables in expressions are understood in the selected stack frame
-(@pxref{Selection, ,Selecting a frame}); they must be either:
+(@pxref{Selection, ,Selecting a Frame}); they must be either:
@itemize @bullet
@item
using the colon-colon (@code{::}) notation:
@cindex colon-colon, context for variables/functions
-@iftex
+@ifnotinfo
@c info cannot cope with a :: index entry, but why deprive hard copy readers?
@cindex @code{::}, context for variables/functions
-@end iftex
+@end ifnotinfo
@smallexample
@var{file}::@var{variable}
@var{function}::@var{variable}
produces debug info in a format that is superior to formats such as
COFF. You may be able to use DWARF 2 (@option{-gdwarf-2}), which is also
an effective form for debug info. @xref{Debugging Options,,Options
-for Debugging Your Program or @sc{gnu} CC, gcc.info, Using @sc{gnu} CC}.
-@xref{C, , Debugging C++}, for more info about debug info formats
+for Debugging Your Program or GCC, gcc.info, Using the @sc{gnu}
+Compiler Collection (GCC)}.
+@xref{C, ,C and C@t{++}}, for more information about debug info formats
that are best suited to C@t{++} programs.
If you ask to print an object whose contents are unknown to
by the debug information, @value{GDBN} will say @samp{<incomplete
type>}. @xref{Symbols, incomplete type}, for more about this.
+Strings are identified as arrays of @code{char} values without specified
+signedness. Arrays of either @code{signed char} or @code{unsigned char} get
+printed as arrays of 1 byte sized integers. @code{-fsigned-char} or
+@code{-funsigned-char} @value{NGCC} options have no effect as @value{GDBN}
+defines literal string type @code{"char"} as @code{char} without a sign.
+For program code
+
+@smallexample
+char var0[] = "A";
+signed char var1[] = "A";
+@end smallexample
+
+You get during debugging
+@smallexample
+(gdb) print var0
+$1 = "A"
+(gdb) print var1
+$2 = @{65 'A', 0 '\0'@}
+@end smallexample
+
@node Arrays
-@section Artificial arrays
+@section Artificial Arrays
@cindex artificial array
@cindex arrays
with @samp{@@} in this way behave just like other arrays in terms of
subscripting, and are coerced to pointers when used in expressions.
Artificial arrays most often appear in expressions via the value history
-(@pxref{Value History, ,Value history}), after printing one out.
+(@pxref{Value History, ,Value History}), after printing one out.
Another way to create an artificial array is to use a cast.
This re-interprets a value as if it were an array.
actually be adjacent---for example, if you are interested in the values
of pointers in an array. One useful work-around in this situation is
to use a convenience variable (@pxref{Convenience Vars, ,Convenience
-variables}) as a counter in an expression that prints the first
+Variables}) as a counter in an expression that prints the first
interesting value, and then repeat that expression via @key{RET}. For
instance, suppose you have an array @code{dtab} of pointers to
structures, and you are interested in the values of a field @code{fv}
@end smallexample
@node Output Formats
-@section Output formats
+@section Output Formats
@cindex formatted output
@cindex output formats
Print as integer in binary. The letter @samp{t} stands for ``two''.
@footnote{@samp{b} cannot be used because these format letters are also
used with the @code{x} command, where @samp{b} stands for ``byte'';
-see @ref{Memory,,Examining memory}.}
+see @ref{Memory,,Examining Memory}.}
@item a
@cindex unknown address, locating
expression. For example, @samp{p/x} reprints the last value in hex.
@node Memory
-@section Examining memory
+@section Examining Memory
You can use the command @code{x} (for ``examine'') to examine memory in
any of several formats, independently of your program's data types.
Even though the unit size @var{u} is ignored for the formats @samp{s}
and @samp{i}, you might still want to use a count @var{n}; for example,
@samp{3i} specifies that you want to see three machine instructions,
-including any operands. The command @code{disassemble} gives an
-alternative way of inspecting machine instructions; see @ref{Machine
-Code,,Source and machine code}.
+including any operands. For convenience, especially when used with
+the @code{display} command, the @samp{i} format also prints branch delay
+slot instructions, if any, beyond the count specified, which immediately
+follow the last instruction that is within the count. The command
+@code{disassemble} gives an alternative way of inspecting machine
+instructions; see @ref{Machine Code,,Source and Machine Code}.
All the defaults for the arguments to @code{x} are designed to make it
easy to continue scanning memory with minimal specifications each time
@cindex remote memory comparison
@cindex verify remote memory image
When you are debugging a program running on a remote target machine
-(@pxref{Remote}), you may wish to verify the program's image in the
+(@pxref{Remote Debugging}), you may wish to verify the program's image in the
remote machine's memory against the executable file you downloaded to
the target. The @code{compare-sections} command is provided for such
situations.
@end table
@node Auto Display
-@section Automatic display
+@section Automatic Display
@cindex automatic display
@cindex display of expressions
For @var{fmt} specifying only a display format and not a size or
count, add the expression @var{expr} to the auto-display list but
arrange to display it each time in the specified format @var{fmt}.
-@xref{Output Formats,,Output formats}.
+@xref{Output Formats,,Output Formats}.
@item display/@var{fmt} @var{addr}
For @var{fmt} @samp{i} or @samp{s}, or including a unit-size or a
number of units, add the expression @var{addr} as a memory address to
be examined each time your program stops. Examining means in effect
-doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining memory}.
+doing @samp{x/@var{fmt} @var{addr}}. @xref{Memory, ,Examining Memory}.
@end table
For example, @samp{display/i $pc} can be helpful, to see the machine
is meaningful, you can enable the display expression once again.
@node Print Settings
-@section Print settings
+@section Print Settings
@cindex format options
@cindex print settings
@item set print repeats
@cindex repeated array elements
Set the threshold for suppressing display of repeated array
-elelments. When the number of consecutive identical elements of an
+elements. When the number of consecutive identical elements of an
array exceeds the threshold, @value{GDBN} prints the string
@code{"<repeats @var{n} times>"}, where @var{n} is the number of
identical repetitions, instead of displaying the identical elements
@item set print pascal_static-members
@itemx set print pascal_static-members on
-@cindex static members of Pacal objects
-@cindex Pacal objects, static members display
+@cindex static members of Pascal objects
+@cindex Pascal objects, static members display
Print static members when displaying a Pascal object. The default is on.
@item set print pascal_static-members off
@end table
@node Value History
-@section Value history
+@section Value History
@cindex value history
@cindex history of values printed by @value{GDBN}
same effect as @samp{show values +}.
@node Convenience Vars
-@section Convenience variables
+@section Convenience Variables
@cindex convenience variables
@cindex user-defined variables
@samp{$} can be used for a convenience variable, unless it is one of
the predefined machine-specific register names (@pxref{Registers, ,Registers}).
(Value history references, in contrast, are @emph{numbers} preceded
-by @samp{$}. @xref{Value History, ,Value history}.)
+by @samp{$}. @xref{Value History, ,Value History}.)
You can save a value in a convenience variable with an assignment
expression, just as you would set a variable in your program.
@vindex $_@r{, convenience variable}
@item $_
The variable @code{$_} is automatically set by the @code{x} command to
-the last address examined (@pxref{Memory, ,Examining memory}). Other
+the last address examined (@pxref{Memory, ,Examining Memory}). Other
commands which provide a default address for @code{x} to examine also
set @code{$_} to that address; these commands include @code{info line}
and @code{info breakpoint}. The type of @code{$_} is @code{void *}
stack frame is selected; setting @code{$sp} is not allowed when other
stack frames are selected. To pop entire frames off the stack,
regardless of machine architecture, use @code{return};
-see @ref{Returning, ,Returning from a function}.} with
+see @ref{Returning, ,Returning from a Function}.} with
@smallexample
set $sp += 4
@end smallexample
Normally, register values are relative to the selected stack frame
-(@pxref{Selection, ,Selecting a frame}). This means that you get the
+(@pxref{Selection, ,Selecting a Frame}). This means that you get the
value that the register would contain if all stack frames farther in
were exited and their saved registers restored. In order to see the
true contents of hardware registers, you must select the innermost
frame makes no difference.
@node Floating Point Hardware
-@section Floating point hardware
+@section Floating Point Hardware
@cindex floating point
Depending on the configuration, @value{GDBN} may be able to give
@end table
@node OS Information
-@section Operating system auxiliary information
+@section Operating System Auxiliary Information
@cindex OS information
@value{GDBN} provides interfaces to useful OS facilities that can help
Depending on the configuration and operating system facilities,
@value{GDBN} may be able to show you this information. For remote
targets, this functionality may further depend on the remote stub's
-support of the @samp{qPart:auxv:read} packet, see @ref{Remote
-configuration, auxiliary vector}.
+support of the @samp{qXfer:auxv:read} packet, see
+@ref{qXfer auxiliary vector read}.
@table @code
@kindex info auxv
@node Memory Region Attributes
-@section Memory region attributes
+@section Memory Region Attributes
@cindex memory region attributes
@dfn{Memory region attributes} allow you to describe special handling
-required by regions of your target's memory. @value{GDBN} uses attributes
-to determine whether to allow certain types of memory accesses; whether to
-use specific width accesses; and whether to cache target memory.
+required by regions of your target's memory. @value{GDBN} uses
+attributes to determine whether to allow certain types of memory
+accesses; whether to use specific width accesses; and whether to cache
+target memory. By default the description of memory regions is
+fetched from the target (if the current target supports this), but the
+user can override the fetched regions.
Defined memory regions can be individually enabled and disabled. When a
memory region is disabled, @value{GDBN} uses the default attributes when
Define a memory region bounded by @var{lower} and @var{upper} with
attributes @var{attributes}@dots{}, and add it to the list of regions
monitored by @value{GDBN}. Note that @var{upper} == 0 is a special
-case: it is treated as the the target's maximum memory address.
+case: it is treated as the target's maximum memory address.
(0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.)
+@item mem auto
+Discard any user changes to the memory regions and use target-supplied
+regions, if available, or no regions if the target does not support.
+
@kindex delete mem
@item delete mem @var{nums}@dots{}
Remove memory regions @var{nums}@dots{} from the list of regions
@end table
@subsubsection Memory Access Size
-The acccess size attributes tells @value{GDBN} to use specific sized
+The access size attribute tells @value{GDBN} to use specific sized
accesses in the memory region. Often memory mapped device registers
require specific sized accesses. If no access size attribute is
specified, @value{GDBN} may use accesses of any size.
Disable @value{GDBN} from caching target memory. This is the default.
@end table
+@subsection Memory Access Checking
+@value{GDBN} can be instructed to refuse accesses to memory that is
+not explicitly described. This can be useful if accessing such
+regions has undesired effects for a specific target, or to provide
+better error checking. The following commands control this behaviour.
+
+@table @code
+@kindex set mem inaccessible-by-default
+@item set mem inaccessible-by-default [on|off]
+If @code{on} is specified, make @value{GDBN} treat memory not
+explicitly described by the memory ranges as non-existent and refuse accesses
+to such memory. The checks are only performed if there's at least one
+memory range defined. If @code{off} is specified, make @value{GDBN}
+treat the memory not explicitly described by the memory ranges as RAM.
+The default value is @code{off}.
+@kindex show mem inaccessible-by-default
+@item show mem inaccessible-by-default
+Show the current handling of accesses to unknown memory.
+@end table
+
+
@c @subsubsection Memory Write Verification
@c The memory write verification attributes set whether @value{GDBN}
@c will re-reads data after each write to verify the write was successful.
@c @end table
@node Dump/Restore Files
-@section Copy between memory and a file
+@section Copy Between Memory and a File
@cindex dump/restore files
@cindex append data to a file
@cindex dump data to a file
For example, if you are running @value{GDBN} on a @sc{gnu}/Linux system, which
uses the ISO Latin 1 character set, but you are using @value{GDBN}'s
-remote protocol (@pxref{Remote,Remote Debugging}) to debug a program
+remote protocol (@pxref{Remote Debugging}) to debug a program
running on an IBM mainframe, which uses the @sc{ebcdic} character set,
then the host character set is Latin-1, and the target character set is
@sc{ebcdic}. If you give @value{GDBN} the command @code{set
@end table
Note that these are all single-byte character sets. More work inside
-GDB is needed to support multi-byte or variable-width character
+@value{GDBN} is needed to support multi-byte or variable-width character
encodings, like the UTF-8 and UCS-2 encodings of Unicode.
Here is an example of @value{GDBN}'s character set support in action.
@cindex caching data of remote targets
@value{GDBN} can cache data exchanged between the debugger and a
-remote target (@pxref{Remote}). Such caching generally improves
+remote target (@pxref{Remote Debugging}). Such caching generally improves
performance, because it reduces the overhead of the remote protocol by
bundling memory reads and writes into large chunks. Unfortunately,
@value{GDBN} does not currently know anything about volatile
@code{ADD} --- but does not expand the invocation of the macro @code{M},
which was introduced by @code{ADD}.
-Once the program is running, GDB uses the macro definitions in force at
-the source line of the current stack frame:
+Once the program is running, @value{GDBN} uses the macro definitions in
+force at the source line of the current stack frame:
@smallexample
(@value{GDBP}) break main
* Tracepoint Passcounts::
* Tracepoint Actions::
* Listing Tracepoints::
-* Starting and Stopping Trace Experiment::
+* Starting and Stopping Trace Experiments::
@end menu
@node Create and Delete Tracepoints
This command can be abbreviated @code{info tp}.
@end table
-@node Starting and Stopping Trace Experiment
-@subsection Starting and Stopping Trace Experiment
+@node Starting and Stopping Trace Experiments
+@subsection Starting and Stopping Trace Experiments
@table @code
@kindex tstart
@node Analyze Collected Data
-@section Using the collected data
+@section Using the Collected Data
After the tracepoint experiment ends, you use @value{GDBN} commands
for examining the trace data. The basic idea is that each tracepoint
* Setting:: Switching between source languages
* Show:: Displaying the language
* Checks:: Type and range checks
-* Supported languages:: Supported languages
-* Unsupported languages:: Unsupported languages
+* Supported Languages:: Supported languages
+* Unsupported Languages:: Unsupported languages
@end menu
@node Setting
-@section Switching between source languages
+@section Switching Between Source Languages
There are two ways to control the working language---either have @value{GDBN}
set it automatically, or select it manually yourself. You can use the
show each frame appropriately for its own language. There is no way to
set the language of a source file from within @value{GDBN}, but you can
set the language associated with a filename extension. @xref{Show, ,
-Displaying the language}.
+Displaying the Language}.
This is most commonly a problem when you use a program, such
as @code{cfront} or @code{f2c}, that generates C but is written in
@end menu
@node Filenames
-@subsection List of filename extensions and languages
+@subsection List of Filename Extensions and Languages
If a source file name ends in one of the following extensions, then
@value{GDBN} infers that its language is the one indicated.
@end table
In addition, you may set the language associated with a filename
-extension. @xref{Show, , Displaying the language}.
+extension. @xref{Show, , Displaying the Language}.
@node Manually
-@subsection Setting the working language
+@subsection Setting the Working Language
If you allow @value{GDBN} to set the language automatically,
expressions are interpreted the same way in your debugging session and
@code{a} to the result of @code{b+c}, yielding a @code{BOOLEAN} value.
@node Automatically
-@subsection Having @value{GDBN} infer the source language
+@subsection Having @value{GDBN} Infer the Source Language
To have @value{GDBN} set the working language automatically, use
@samp{set language local} or @samp{set language auto}. @value{GDBN}
case frees you from having to set the working language manually.
@node Show
-@section Displaying the language
+@section Displaying the Language
The following commands help you find out which language is the
working language, and also what language source files were written in.
@kindex info frame@r{, show the source language}
Display the source language for this frame. This language becomes the
working language if you use an identifier from this frame.
-@xref{Frame Info, ,Information about a frame}, to identify the other
+@xref{Frame Info, ,Information about a Frame}, to identify the other
information listed here.
@item info source
@end table
@node Checks
-@section Type and range checking
+@section Type and Range Checking
@quotation
@emph{Warning:} In this release, the @value{GDBN} commands for type and range
evaluation via the @code{print} command, for example. As with the
working language, @value{GDBN} can also decide whether or not to check
automatically based on your program's source language.
-@xref{Supported languages, ,Supported languages}, for the default
+@xref{Supported Languages, ,Supported Languages}, for the default
settings of supported languages.
@menu
@cindex type checking
@cindex checks, type
@node Type Checking
-@subsection An overview of type checking
+@subsection An Overview of Type Checking
Some languages, such as Modula-2, are strongly typed, meaning that the
arguments to operators and functions have to be of the correct type,
instance, both Modula-2 and C require the arguments to arithmetical
operators to be numbers. In C, enumerated types and pointers can be
represented as numbers, so that they are valid arguments to mathematical
-operators. @xref{Supported languages, ,Supported languages}, for further
+operators. @xref{Supported Languages, ,Supported Languages}, for further
details on specific languages.
@value{GDBN} provides some additional commands for controlling the type checker:
@table @code
@item set check type auto
Set type checking on or off based on the current working language.
-@xref{Supported languages, ,Supported languages}, for the default settings for
+@xref{Supported Languages, ,Supported Languages}, for the default settings for
each language.
@item set check type on
@cindex range checking
@cindex checks, range
@node Range Checking
-@subsection An overview of range checking
+@subsection An Overview of Range Checking
In some languages (such as Modula-2), it is an error to exceed the
bounds of a type; this is enforced with run-time checks. Such range
@end smallexample
This, too, is specific to individual languages, and in some cases
-specific to individual compilers or machines. @xref{Supported languages, ,
-Supported languages}, for further details on specific languages.
+specific to individual compilers or machines. @xref{Supported Languages, ,
+Supported Languages}, for further details on specific languages.
@value{GDBN} provides some additional commands for controlling the range checker:
@table @code
@item set check range auto
Set range checking on or off based on the current working language.
-@xref{Supported languages, ,Supported languages}, for the default settings for
+@xref{Supported Languages, ,Supported Languages}, for the default settings for
each language.
@item set check range on
being set automatically by @value{GDBN}.
@end table
-@node Supported languages
-@section Supported languages
+@node Supported Languages
+@section Supported Languages
@value{GDBN} supports C, C@t{++}, Objective-C, Fortran, Java, Pascal,
assembly, Modula-2, and Ada.
format; if it doesn't work on your system, try the stabs+ debugging
format. You can select those formats explicitly with the @code{g++}
command-line options @option{-gdwarf-2} and @option{-gstabs+}.
-@xref{Debugging Options,,Options for Debugging Your Program or @sc{gnu}
-CC, gcc.info, Using @sc{gnu} CC}.
+@xref{Debugging Options,,Options for Debugging Your Program or GCC,
+gcc.info, Using the @sc{gnu} Compiler Collection (GCC)}.
@menu
* C Operators:: C and C@t{++} operators
* C Constants:: C and C@t{++} constants
-* C plus plus expressions:: C@t{++} expressions
+* C Plus Plus Expressions:: C@t{++} expressions
* C Defaults:: Default settings for C and C@t{++}
* C Checks:: C and C@t{++} type and range checks
* Debugging C:: @value{GDBN} and C
-* Debugging C plus plus:: @value{GDBN} features for C@t{++}
+* Debugging C Plus Plus:: @value{GDBN} features for C@t{++}
@end menu
@node C Operators
-@subsubsection C and C@t{++} operators
+@subsubsection C and C@t{++} Operators
@cindex C and C@t{++} operators
attempts to invoke the redefined version instead of using the operator's
predefined meaning.
-@menu
-* C Constants::
-@end menu
-
@node C Constants
-@subsubsection C and C@t{++} constants
+@subsubsection C and C@t{++} Constants
@cindex C and C@t{++} constants
and @samp{@{&"hi", &"there", &"fred"@}} is a three-element array of pointers.
@end itemize
-@menu
-* C plus plus expressions::
-* C Defaults::
-* C Checks::
-
-* Debugging C::
-@end menu
-
-@node C plus plus expressions
-@subsubsection C@t{++} expressions
+@node C Plus Plus Expressions
+@subsubsection C@t{++} Expressions
@cindex expressions in C@t{++}
@value{GDBN} expression handling can interpret most C@t{++} expressions.
number of function arguments.
Overload resolution is always performed, unless you have specified
-@code{set overload-resolution off}. @xref{Debugging C plus plus,
-,@value{GDBN} features for C@t{++}}.
+@code{set overload-resolution off}. @xref{Debugging C Plus Plus,
+,@value{GDBN} Features for C@t{++}}.
You must specify @code{set overload-resolution off} in order to use an
explicit function signature to call an overloaded function, as in
@end smallexample
The @value{GDBN} command-completion facility can simplify this;
-see @ref{Completion, ,Command completion}.
+see @ref{Completion, ,Command Completion}.
@cindex reference declarations
@item
necessary, for example in an expression like
@samp{@var{scope1}::@var{scope2}::@var{name}}. @value{GDBN} also allows
resolving name scope by reference to source files, in both C and C@t{++}
-debugging (@pxref{Variables, ,Program variables}).
+debugging (@pxref{Variables, ,Program Variables}).
@end enumerate
In addition, when used with HP's C@t{++} compiler, @value{GDBN} supports
invoking user-defined operators.
@node C Defaults
-@subsubsection C and C@t{++} defaults
+@subsubsection C and C@t{++} Defaults
@cindex C and C@t{++} defaults
recognizes source files whose names end with @file{.c}, @file{.C}, or
@file{.cc}, etc, and when @value{GDBN} enters code compiled from one of
these files, it sets the working language to C or C@t{++}.
-@xref{Automatically, ,Having @value{GDBN} infer the source language},
+@xref{Automatically, ,Having @value{GDBN} Infer the Source Language},
for further details.
@c Type checking is (a) primarily motivated by Modula-2, and (b)
@c appear even if Mod-2 does not, but meanwhile ignore it. roland 16jul93.
@node C Checks
-@subsubsection C and C@t{++} type and range checks
+@subsubsection C and C@t{++} Type and Range Checks
@cindex C and C@t{++} checks
with pointers and a memory allocation function. @xref{Expressions,
,Expressions}.
-@menu
-* Debugging C plus plus::
-@end menu
-
-@node Debugging C plus plus
-@subsubsection @value{GDBN} features for C@t{++}
+@node Debugging C Plus Plus
+@subsubsection @value{GDBN} Features for C@t{++}
@cindex commands for C@t{++}
@item @r{breakpoint menus}
When you want a breakpoint in a function whose name is overloaded,
@value{GDBN} breakpoint menus help you specify which function definition
-you want. @xref{Breakpoint Menus,,Breakpoint menus}.
+you want. @xref{Breakpoint Menus,,Breakpoint Menus}.
@cindex overloading in C@t{++}
@item rbreak @var{regex}
Setting breakpoints using regular expressions is helpful for setting
breakpoints on overloaded functions that are not members of any special
classes.
-@xref{Set Breaks, ,Setting breakpoints}.
+@xref{Set Breaks, ,Setting Breakpoints}.
@cindex C@t{++} exception handling
@item catch throw
@itemx catch catch
Debug C@t{++} exception handling using these commands. @xref{Set
-Catchpoints, , Setting catchpoints}.
+Catchpoints, , Setting Catchpoints}.
@cindex inheritance
@item ptype @var{typename}
@itemx show print asm-demangle
Control whether C@t{++} symbols display in their source form, both when
displaying code as C@t{++} source and when displaying disassemblies.
-@xref{Print Settings, ,Print settings}.
+@xref{Print Settings, ,Print Settings}.
@item set print object
@itemx show print object
Choose whether to print derived (actual) or declared types of objects.
-@xref{Print Settings, ,Print settings}.
+@xref{Print Settings, ,Print Settings}.
@item set print vtbl
@itemx show print vtbl
Control the format for printing virtual function tables.
-@xref{Print Settings, ,Print settings}.
+@xref{Print Settings, ,Print Settings}.
(The @code{vtbl} commands do not work on programs compiled with the HP
ANSI C@t{++} compiler (@code{aCC}).)
Enable overload resolution for C@t{++} expression evaluation. The default
is on. For overloaded functions, @value{GDBN} evaluates the arguments
and searches for a function whose signature matches the argument types,
-using the standard C@t{++} conversion rules (see @ref{C plus plus expressions, ,C@t{++}
-expressions}, for details). If it cannot find a match, it emits a
-message.
+using the standard C@t{++} conversion rules (see @ref{C Plus Plus
+Expressions, ,C@t{++} Expressions}, for details).
+If it cannot find a match, it emits a message.
@item set overload-resolution off
Disable overload resolution for C@t{++} expression evaluation. For
@code{@var{symbol}(@var{types})} rather than just @var{symbol}. You can
also use the @value{GDBN} command-line word completion facilities to list the
available choices, or to finish the type list for you.
-@xref{Completion,, Command completion}, for details on how to do this.
+@xref{Completion,, Command Completion}, for details on how to do this.
@end table
@node Objective-C
* The Print Command with Objective-C::
@end menu
-@node Method Names in Commands, The Print Command with Objective-C, Objective-C, Objective-C
+@node Method Names in Commands
@subsubsection Method Names in Commands
The following commands have been extended to accept Objective-C method
@menu
* Fortran Operators:: Fortran operators and expressions
* Fortran Defaults:: Default settings for Fortran
-* Special Fortran commands:: Special @value{GDBN} commands for Fortran
+* Special Fortran Commands:: Special @value{GDBN} commands for Fortran
@end menu
@node Fortran Operators
-@subsubsection Fortran operators and expressions
+@subsubsection Fortran Operators and Expressions
@cindex Fortran operators and expressions
change that with the @samp{set case-insensitive} command, see
@ref{Symbols}, for the details.
-@node Special Fortran commands
-@subsubsection Special Fortran commands
+@node Special Fortran Commands
+@subsubsection Special Fortran Commands
@cindex Special Fortran commands
-@value{GDBN} had some commands to support Fortran specific feature,
-such as common block displaying.
+@value{GDBN} has some commands to support Fortran-specific features,
+such as displaying common blocks.
@table @code
@cindex @code{COMMON} blocks, Fortran
@item info common @r{[}@var{common-name}@r{]}
This command prints the values contained in the Fortran @code{COMMON}
block whose name is @var{common-name}. With no argument, the names of
-all @code{COMMON} blocks visible at current program location are
+all @code{COMMON} blocks visible at the current program location are
printed.
@end table
@node Built-In Func/Proc
-@subsubsection Built-in functions and procedures
+@subsubsection Built-in Functions and Procedures
@cindex Modula-2 built-ins
Modula-2 also makes available several built-in procedures and functions.
String constants consist of a sequence of characters enclosed by a
pair of like quotes, either single (@code{'}) or double (@code{"}).
Escape sequences in the style of C are also allowed. @xref{C
-Constants, ,C and C@t{++} constants}, for a brief explanation of escape
+Constants, ,C and C@t{++} Constants}, for a brief explanation of escape
sequences.
@item
@end smallexample
@node M2 Defaults
-@subsubsection Modula-2 defaults
+@subsubsection Modula-2 Defaults
@cindex Modula-2 defaults
If type and range checking are set automatically by @value{GDBN}, they
If you allow @value{GDBN} to set the language automatically, then entering
code compiled from a file whose name ends with @file{.mod} sets the
-working language to Modula-2. @xref{Automatically, ,Having @value{GDBN} set
-the language automatically}, for further details.
+working language to Modula-2. @xref{Automatically, ,Having @value{GDBN}
+Infer the Source Language}, for further details.
@node Deviations
-@subsubsection Deviations from standard Modula-2
+@subsubsection Deviations from Standard Modula-2
@cindex Modula-2, deviations from
A few changes have been made to make Modula-2 programs easier to debug.
@end itemize
@node M2 Checks
-@subsubsection Modula-2 type and range checks
+@subsubsection Modula-2 Type and Range Checks
@cindex Modula-2 checks
@quotation
index bounds, and all built-in functions and procedures.
@node M2 Scope
-@subsubsection The scope operators @code{::} and @code{.}
+@subsubsection The Scope Operators @code{::} and @code{.}
@cindex scope
@cindex @code{.}, Modula-2 scope operator
@cindex colon, doubled as scope operator
@item
The overloading algorithm is much more limited (i.e., less selective)
-than that of real Ada. It makes only limited use of the context in which a subexpression
-appears to resolve its meaning, and it is much looser in its rules for allowing
-type matches. As a result, some function calls will be ambiguous, and the user
-will be asked to choose the proper resolution.
+than that of real Ada. It makes only limited use of the context in
+which a subexpression appears to resolve its meaning, and it is much
+looser in its rules for allowing type matches. As a result, some
+function calls will be ambiguous, and the user will be asked to choose
+the proper resolution.
@item
The @code{new} operator is not implemented.
@itemize @bullet
@item
-If the expression @var{E} is a variable residing in memory
-(typically a local variable or array element) and @var{N} is
-a positive integer, then @code{@var{E}@@@var{N}} displays the values of
-@var{E} and the @var{N}-1 adjacent variables following it in memory as an array.
-In Ada, this operator is generally not necessary, since its prime use
-is in displaying parts of an array, and slicing will usually do this in Ada.
-However, there are occasional uses when debugging programs
-in which certain debugging information has been optimized away.
+If the expression @var{E} is a variable residing in memory (typically
+a local variable or array element) and @var{N} is a positive integer,
+then @code{@var{E}@@@var{N}} displays the values of @var{E} and the
+@var{N}-1 adjacent variables following it in memory as an array. In
+Ada, this operator is generally not necessary, since its prime use is
+in displaying parts of an array, and slicing will usually do this in
+Ada. However, there are occasional uses when debugging programs in
+which certain debugging information has been optimized away.
@item
-@code{@var{B}::@var{var}} means ``the variable named @var{var} that appears
-in function or file @var{B}.'' When @var{B} is a file name, you must typically
-surround it in single quotes.
+@code{@var{B}::@var{var}} means ``the variable named @var{var} that
+appears in function or file @var{B}.'' When @var{B} is a file name,
+you must typically surround it in single quotes.
@item
The expression @code{@{@var{type}@} @var{addr}} means ``the variable of type
(@pxref{Convenience Vars}) or a machine register (@pxref{Registers}).
@end itemize
-In addition, @value{GDBN} provides a few other shortcuts and outright additions specific
-to Ada:
+In addition, @value{GDBN} provides a few other shortcuts and outright
+additions specific to Ada:
@itemize @bullet
@item
"One line.["0a"]Next line.["0a"]"
@end smallexample
@noindent
-contains an ASCII newline character (@code{Ada.Characters.Latin_1.LF}) after each
-period.
+contains an ASCII newline character (@code{Ada.Characters.Latin_1.LF})
+after each period.
@item
The subtype used as a prefix for the attributes @t{'Pos}, @t{'Min}, and
@item
When printing arrays, @value{GDBN} uses positional notation when the
array has a lower bound of 1, and uses a modified named notation otherwise.
-For example, a one-dimensional array of three integers with a lower bound of 3 might print as
+For example, a one-dimensional array of three integers with a lower bound
+of 3 might print as
@smallexample
(3 => 10, 17, 1)
@code{Standard} explicitly.
@end itemize
-@node Unsupported languages
-@section Unsupported languages
+@node Unsupported Languages
+@section Unsupported Languages
@cindex unsupported languages
@cindex minimal language
program. This information is inherent in the text of your program and
does not change as your program executes. @value{GDBN} finds it in your
program's symbol table, in the file indicated when you started @value{GDBN}
-(@pxref{File Options, ,Choosing files}), or by one of the
-file-management commands (@pxref{Files, ,Commands to specify files}).
+(@pxref{File Options, ,Choosing Files}), or by one of the
+file-management commands (@pxref{Files, ,Commands to Specify Files}).
@cindex symbol names
@cindex names of symbols
Occasionally, you may need to refer to symbols that contain unusual
characters, which @value{GDBN} ordinarily treats as word delimiters. The
most frequent case is in referring to static variables in other
-source files (@pxref{Variables,,Program variables}). File names
+source files (@pxref{Variables,,Program Variables}). File names
are recorded in object files as debugging symbols, but @value{GDBN} would
ordinarily parse a typical file name, like @file{foo.c}, as the three words
@samp{foo} @samp{.} @samp{c}. To allow @value{GDBN} to recognize
files that @value{GDBN} has skimmed, but not yet read completely. Finally,
@samp{maint print msymbols} dumps just the minimal symbol information
required for each object file from which @value{GDBN} has read some symbols.
-@xref{Files, ,Commands to specify files}, for a discussion of how
+@xref{Files, ,Commands to Specify Files}, for a discussion of how
@value{GDBN} reads symbols (in the description of @code{symbol-file}).
@kindex maint info symtabs
@end menu
@node Assignment
-@section Assignment to variables
+@section Assignment to Variables
@cindex assignment
@cindex setting variables
@code{set} command instead of the @code{print} command. @code{set} is
really the same as @code{print} except that the expression's value is
not printed and is not put in the value history (@pxref{Value History,
-,Value history}). The expression is evaluated only for its effects.
+,Value History}). The expression is evaluated only for its effects.
If the beginning of the argument string of the @code{set} command
appears identical to a @code{set} subcommand, use the @code{set
stores the value 4 into that memory location.
@node Jumping
-@section Continuing at a different address
+@section Continuing at a Different Address
Ordinarily, when you continue your program, you do so at the place where
it stopped, with the @code{continue} command. You can instead continue at
@item jump @var{linespec}
Resume execution at line @var{linespec}. Execution stops again
immediately if there is a breakpoint there. @xref{List, ,Printing
-source lines}, for a description of the different forms of
+Source Lines}, for a description of the different forms of
@var{linespec}. It is common practice to use the @code{tbreak} command
in conjunction with @code{jump}. @xref{Set Breaks, ,Setting
-breakpoints}.
+Breakpoints}.
The @code{jump} command does not change the current stack frame, or
the stack pointer, or the contents of any memory location or any
@noindent
makes the next @code{continue} command or stepping command execute at
address @code{0x485}, rather than at the address where your program stopped.
-@xref{Continuing and Stepping, ,Continuing and stepping}.
+@xref{Continuing and Stepping, ,Continuing and Stepping}.
The most common occasion to use the @code{jump} command is to back
up---perhaps with more breakpoints set---over a portion of a program
@c @group
@node Signaling
-@section Giving your program a signal
+@section Giving your Program a Signal
@cindex deliver a signal to a program
@table @code
@node Returning
-@section Returning from a function
+@section Returning from a Function
@table @code
@cindex returning from a function
be returned, give that value as the argument to @code{return}.
This pops the selected stack frame (@pxref{Selection, ,Selecting a
-frame}), and any other frames inside of it, leaving its caller as the
+Frame}), and any other frames inside of it, leaving its caller as the
innermost remaining frame. That frame becomes selected. The
specified value is stored in the registers used for returning values
of functions.
The @code{return} command does not resume execution; it leaves the
program stopped in the state that would exist if the function had just
returned. In contrast, the @code{finish} command (@pxref{Continuing
-and Stepping, ,Continuing and stepping}) resumes execution until the
+and Stepping, ,Continuing and Stepping}) resumes execution until the
selected stack frame returns naturally.
@node Calling
-@section Calling program functions
+@section Calling Program Functions
@table @code
@cindex calling functions
@cindex inferior functions, calling
@item print @var{expr}
-Evaluate the expression @var{expr} and display the resuling value.
+Evaluate the expression @var{expr} and display the resulting value.
@var{expr} may include calls to functions in the program being
debugged.
function instead.
@node Patching
-@section Patching programs
+@section Patching Programs
@cindex patching binaries
@cindex writing into executables
@end menu
@node Files
-@section Commands to specify files
+@section Commands to Specify Files
@cindex symbol table
@cindex core dump file
Occasionally it is necessary to change to a different file during a
@value{GDBN} session. Or you may run @value{GDBN} and forget to
specify a file you want to use. Or you are debugging a remote target
-via @code{gdbserver} (@pxref{Server, file}). In these situations the
-@value{GDBN} commands to specify new files are useful.
+via @code{gdbserver} (@pxref{Server, file, Using the @code{gdbserver}
+Program}). In these situations the @value{GDBN} commands to specify
+new files are useful.
@table @code
@cindex executable file
generated for that environment; you may use either a @sc{gnu} compiler, or
other compilers that adhere to the local conventions.
Best results are usually obtained from @sc{gnu} compilers; for example,
-using @code{@value{GCC}} you can generate debugging information for
+using @code{@value{NGCC}} you can generate debugging information for
optimized code.
For most kinds of object files, with the exception of old SVR3 systems
occasional pauses while the symbol table details for a particular source
file are being read. (The @code{set verbose} command can turn these
pauses into messages if desired. @xref{Messages/Warnings, ,Optional
-warnings and messages}.)
+Warnings and Messages}.)
We have not implemented the two-stage strategy for COFF yet. When the
symbol table is stored in COFF format, @code{symbol-file} reads the
under @value{GDBN}. So, if you have been running your program and you
wish to debug a core file instead, you must kill the subprocess in which
the program is running. To do this, use the @code{kill} command
-(@pxref{Kill Process, ,Killing the child process}).
+(@pxref{Kill Process, ,Killing the Child Process}).
@kindex add-symbol-file
@cindex dynamic linking
symbols from shared libraries. To that end, type @kbd{set
auto-solib-add off} before running the inferior, then load each
library whose debug symbols you do need with @kbd{sharedlibrary
-@var{regexp}}, where @var{regexp} is a regular expresion that matches
+@var{regexp}}, where @var{regexp} is a regular expression that matches
the libraries whose symbols you want to be loaded.
@kindex show auto-solib-add
@table @code
@cindex prefix for shared library file names
+@cindex system root, alternate
@kindex set solib-absolute-prefix
-@item set solib-absolute-prefix @var{path}
-If this variable is set, @var{path} will be used as a prefix for any
-absolute shared library paths; many runtime loaders store the absolute
-paths to the shared library in the target program's memory. If you use
-@samp{solib-absolute-prefix} to find shared libraries, they need to be laid
-out in the same way that they are on the target, with e.g.@: a
-@file{/usr/lib} hierarchy under @var{path}.
-
-@cindex default value of @samp{solib-absolute-prefix}
+@kindex set sysroot
+@item set sysroot @var{path}
+Use @var{path} as the system root for the program being debugged. Any
+absolute shared library paths will be prefixed with @var{path}; many
+runtime loaders store the absolute paths to the shared library in the
+target program's memory. If you use @code{set sysroot} to find shared
+libraries, they need to be laid out in the same way that they are on
+the target, with e.g.@: a @file{/lib} and @file{/usr/lib} hierarchy
+under @var{path}.
+
+The @code{set solib-absolute-prefix} command is an alias for @code{set
+sysroot}.
+
+@cindex default system root
@cindex @samp{--with-sysroot}
-You can set the default value of @samp{solib-absolute-prefix} by using the
-configure-time @samp{--with-sysroot} option.
-
-@kindex show solib-absolute-prefix
-@item show solib-absolute-prefix
+You can set the default system root by using the configure-time
+@samp{--with-sysroot} option. If the system root is inside
+@value{GDBN}'s configured binary prefix (set with @samp{--prefix} or
+@samp{--exec-prefix}), then the default system root will be updated
+automatically if the installed @value{GDBN} is moved to a new
+location.
+
+@kindex show sysroot
+@item show sysroot
Display the current shared library prefix.
@kindex set solib-search-path
@item set solib-search-path @var{path}
-If this variable is set, @var{path} is a colon-separated list of directories
-to search for shared libraries. @samp{solib-search-path} is used after
-@samp{solib-absolute-prefix} fails to locate the library, or if the path to
-the library is relative instead of absolute. If you want to use
-@samp{solib-search-path} instead of @samp{solib-absolute-prefix}, be sure to
-set @samp{solib-absolute-prefix} to a nonexistant directory to prevent
-@value{GDBN} from finding your host's libraries.
+If this variable is set, @var{path} is a colon-separated list of
+directories to search for shared libraries. @samp{solib-search-path}
+is used after @samp{sysroot} fails to locate the library, or if the
+path to the library is relative instead of absolute. If you want to
+use @samp{solib-search-path} instead of @samp{sysroot}, be sure to set
+@samp{sysroot} to a nonexistent directory to prevent @value{GDBN} from
+finding your host's libraries. @samp{sysroot} is preferred; setting
+it to a nonexistent directory may interfere with automatic loading
+of shared library symbols.
@kindex show solib-search-path
@item show solib-search-path
@cindex @file{.debug} subdirectories
@cindex debugging information directory, global
@cindex global debugging information directory
+@cindex build ID, and separate debugging files
+@cindex @file{.build-id} directory
@value{GDBN} allows you to put a program's debugging information in a
file separate from the executable itself, in a way that allows
@value{GDBN} to find and load the debugging information automatically.
-Since debugging information can be very large --- sometimes larger
-than the executable code itself --- some systems distribute debugging
+Since debugging information can be very large---sometimes larger
+than the executable code itself---some systems distribute debugging
information for their executables in separate files, which users can
install only when they need to debug a problem.
-If an executable's debugging information has been extracted to a
-separate file, the executable should contain a @dfn{debug link} giving
-the name of the debugging information file (with no directory
-components), and a checksum of its contents. (The exact form of a
-debug link is described below.) If the full name of the directory
-containing the executable is @var{execdir}, and the executable has a
-debug link that specifies the name @var{debugfile}, then @value{GDBN}
-will automatically search for the debugging information file in three
-places:
+@value{GDBN} supports two ways of specifying the separate debug info
+file:
@itemize @bullet
@item
-the directory containing the executable file (that is, it will look
-for a file named @file{@var{execdir}/@var{debugfile}},
+The executable contains a @dfn{debug link} that specifies the name of
+the separate debug info file. The separate debug file's name is
+usually @file{@var{executable}.debug}, where @var{executable} is the
+name of the corresponding executable file without leading directories
+(e.g., @file{ls.debug} for @file{/usr/bin/ls}). In addition, the
+debug link specifies a CRC32 checksum for the debug file, which
+@value{GDBN} uses to validate that the executable and the debug file
+came from the same build.
+
+@item
+The executable contains a @dfn{build ID}, a unique signature that is
+also present in the corresponding debug info file. (This is supported
+only on some operating systems, notably on @sc{gnu}/Linux. For more
+details about this feature, see
+@uref{http://fedoraproject.org/wiki/Releases/FeatureBuildId, the
+Fedora Project's description of the buid ID feature}.) The debug info
+file's name is not specified explicitly by the debug ID, but can be
+computed from the build ID, see below.
+@end itemize
+
+Depending on the way the debug info file is specified, @value{GDBN}
+uses two different methods of looking for the debug file:
+
+@itemize @bullet
@item
-a subdirectory of that directory named @file{.debug} (that is, the
-file @file{@var{execdir}/.debug/@var{debugfile}}, and
+For the ``debug link'' method, @value{GDBN} looks up the named file in
+the directory of the executable file, then in a subdirectory of that
+directory named @file{.debug}, and finally under the global debug
+directory, in a subdirectory whose name is identical to the leading
+directories of the executable's absolute file name.
+
@item
-a subdirectory of the global debug file directory that includes the
-executable's full path, and the name from the link (that is, the file
-@file{@var{globaldebugdir}/@var{execdir}/@var{debugfile}}, where
-@var{globaldebugdir} is the global debug file directory, and
-@var{execdir} has been turned into a relative path).
+For the ``debug ID'' method, @value{GDBN} looks in the
+@file{.build-id} subdirectory of the global debug directory for a file
+named @file{@var{nn}/@var{nnnnnnnn}.debug}, where @var{nn} are the
+first 2 hex characters of the debug ID signature, and @var{nnnnnnnn}
+are the rest of the signature. (Real signatures are 32 or more
+characters, not 10.)
@end itemize
-@noindent
-@value{GDBN} checks under each of these names for a debugging
-information file whose checksum matches that given in the link, and
-reads the debugging information from the first one it finds.
-
-So, for example, if you ask @value{GDBN} to debug @file{/usr/bin/ls},
-which has a link containing the name @file{ls.debug}, and the global
-debug directory is @file{/usr/lib/debug}, then @value{GDBN} will look
-for debug information in @file{/usr/bin/ls.debug},
-@file{/usr/bin/.debug/ls.debug}, and
+
+So, for example, suppose you ask @value{GDBN} to debug
+@file{/usr/bin/ls}, which has a @dfn{debug link} that specifies the
+file @file{ls.debug}, and a @dfn{build id} whose value in hex is
+@code{abcdef1234}. If the global debug directory is
+@file{/usr/lib/debug}, then @value{GDBN} will look for the following
+debug information files, in the indicated order:
+
+@itemize @minus
+@item
+@file{/usr/lib/debug/.build-id/ab/cdef1234.debug}
+@item
+@file{/usr/bin/ls.debug}
+@item
+@file{/usr/bin/.debug/ls.debug}
+@item
@file{/usr/lib/debug/usr/bin/ls.debug}.
+@end itemize
You can set the global debugging info directory's name, and view the
name @value{GDBN} is currently using.
@end table
@cindex @code{.gnu_debuglink} sections
-@cindex debug links
+@cindex debug link sections
A debug link is a special section of the executable file named
@code{.gnu_debuglink}. The section must contain:
contain a section named @code{.gnu_debuglink} with the contents
described above.
+@cindex @code{.note.gnu.build-id} sections
+@cindex build ID sections
+A build ID is a special section of the executable file named
+@code{.note.gnu.build-id}. This section contains unique
+identification for the built files---it remains the same across
+multiple builds of the same build tree. The default algorithm SHA1
+produces 160 bits (40 hexadecimal characters) of the content. The
+same section with an identical value is present in the original built
+binary with symbols, in its stripped variant, and in the separate
+debugging information file.
+
The debugging information file itself should be an ordinary
executable, containing a full set of linker symbols, sections, and
debugging information. The sections of the debugging information file
-should have the same names, addresses and sizes as the original file,
-but they need not contain any data --- much like a @code{.bss} section
+should have the same names, addresses, and sizes as the original file,
+but they need not contain any data---much like a @code{.bss} section
in an ordinary executable.
-As of December 2002, there is no standard GNU utility to produce
-separated executable / debugging information file pairs. Ulrich
-Drepper's @file{elfutils} package, starting with version 0.53,
-contains a version of the @code{strip} command such that the command
-@kbd{strip foo -f foo.debug} removes the debugging information from
-the executable file @file{foo}, places it in the file
-@file{foo.debug}, and leaves behind a debug link in @file{foo}.
+@sc{gnu} binary utilities (Binutils) package includes the
+@samp{objcopy} utility that can produce
+the separated executable / debugging information file pairs using the
+following commands:
+
+@smallexample
+@kbd{objcopy --only-keep-debug foo foo.debug}
+@kbd{strip -g foo}
+@kbd{objcopy --add-gnu-debuglink="foo.debug" "foo"}
+@end smallexample
-Since there are many different ways to compute CRC's (different
-polynomials, reversals, byte ordering, etc.), the simplest way to
-describe the CRC used in @code{.gnu_debuglink} sections is to give the
-complete code for a function that computes it:
+@noindent
+These commands remove the debugging
+information from the executable file @file{foo}, place it in the file
+@file{foo.debug}, and leave behind a debug link in @file{foo}. Ulrich
+Drepper's @file{elfutils} package, starting with version 0.53, contains
+a version of the @code{strip} command such that the command @kbd{strip foo -f
+foo.debug} has the same functionality as the three commands above.
+
+Since there are many different ways to compute CRC's for the debug
+link (different polynomials, reversals, byte ordering, etc.), the
+simplest way to describe the CRC used in @code{.gnu_debuglink}
+sections is to give the complete code for a function that computes it:
@kindex gnu_debuglink_crc32
@smallexample
@}
@end smallexample
+@noindent
+This computation does not apply to the ``build ID'' method.
+
@node Symbol Errors
-@section Errors reading symbol files
+@section Errors Reading Symbol Files
While reading a symbol file, @value{GDBN} occasionally encounters problems,
such as symbol types it does not recognize, or known bugs in compiler
only one message about each such type of problem, no matter how many
times the problem occurs; or you can ask @value{GDBN} to print more messages,
to see how many times the problems occur, with the @code{set
-complaints} command (@pxref{Messages/Warnings, ,Optional warnings and
-messages}).
+complaints} command (@pxref{Messages/Warnings, ,Optional Warnings and
+Messages}).
The messages currently printed, and their meanings, include:
@value{GDBN} does not circumvent this problem, and has trouble
locating symbols in the source file whose symbols it is reading. (You
can often determine what source file is affected by specifying
-@code{set verbose on}. @xref{Messages/Warnings, ,Optional warnings and
-messages}.)
+@code{set verbose on}. @xref{Messages/Warnings, ,Optional Warnings and
+Messages}.)
@item bad block start address patched
host, or controlling a standalone system over a serial port or a
realtime system over a TCP/IP connection---you can use the @code{target}
command to specify one of the target types configured for @value{GDBN}
-(@pxref{Target Commands, ,Commands for managing targets}).
+(@pxref{Target Commands, ,Commands for Managing Targets}).
@cindex target architecture
It is possible to build @value{GDBN} for several different @dfn{target
* Active Targets:: Active targets
* Target Commands:: Commands for managing targets
* Byte Order:: Choosing target byte order
-* Remote:: Remote debugging
-* KOD:: Kernel Object Display
-
@end menu
@node Active Targets
-@section Active targets
+@section Active Targets
@cindex stacking targets
@cindex active targets
process target is active.
Use the @code{core-file} and @code{exec-file} commands to select a new
-core file or executable target (@pxref{Files, ,Commands to specify
-files}). To specify as a target a process that is already running, use
-the @code{attach} command (@pxref{Attach, ,Debugging an already-running
-process}).
+core file or executable target (@pxref{Files, ,Commands to Specify
+Files}). To specify as a target a process that is already running, use
+the @code{attach} command (@pxref{Attach, ,Debugging an Already-running
+Process}).
@node Target Commands
-@section Commands for managing targets
+@section Commands for Managing Targets
@table @code
@item target @var{type} @var{parameters}
@item help target
Displays the names of all targets available. To display targets
currently selected, use either @code{info target} or @code{info files}
-(@pxref{Files, ,Commands to specify files}).
+(@pxref{Files, ,Commands to Specify Files}).
@item help target @var{name}
Describe a particular target, including any parameters necessary to
@end quotation
@noindent
-@xref{Files, , Commands to specify files}.
+@xref{Files, , Commands to Specify Files}.
@kindex show gnutarget
@item show gnutarget
Many remote targets require you to download the executable's code once
you've successfully established a connection. You may wish to control
-various aspects of this process, such as the size of the data chunks
-used by @value{GDBN} to download program parts to the remote target.
+various aspects of this process.
@table @code
-@kindex set download-write-size
-@item set download-write-size @var{size}
-Set the write size used when downloading a program. Only used when
-downloading a program onto a remote target. Specify zero or a
-negative value to disable blocked writes. The actual size of each
-transfer is also limited by the size of the target packet and the
-memory cache.
-
-@kindex show download-write-size
-@item show download-write-size
-@kindex show download-write-size
-Show the current value of the write size.
@item set hash
@kindex set hash@r{, for remote monitors}
specifies a fixed address.
@c FIXME! This would be a good place for an xref to the GNU linker doc.
+Depending on the remote side capabilities, @value{GDBN} may be able to
+load programs into flash memory.
+
@code{load} does not repeat if you press @key{RET} again after using it.
@end table
@node Byte Order
-@section Choosing target byte order
+@section Choosing Target Byte Order
@cindex choosing target byte order
@cindex target byte order
data on the host, and that they have absolutely no effect on the
target system.
-@node Remote
-@section Remote debugging
+
+@node Remote Debugging
+@chapter Debugging Remote Programs
@cindex remote debugging
If you are trying to debug a program running on a machine that cannot run
Other remote targets may be available in your
configuration of @value{GDBN}; use @code{help target} to list them.
-Once you've connected to the remote target, @value{GDBN} allows you to
-send arbitrary commands to the remote monitor:
-
-@table @code
-@item remote @var{command}
-@kindex remote@r{, a command}
-@cindex send command to remote monitor
-Send an arbitrary @var{command} string to the remote monitor.
-@end table
-
-
-@node KOD
-@section Kernel Object Display
-@cindex kernel object display
-@cindex KOD
-
-Some targets support kernel object display. Using this facility,
-@value{GDBN} communicates specially with the underlying operating system
-and can display information about operating system-level objects such as
-mutexes and other synchronization objects. Exactly which objects can be
-displayed is determined on a per-OS basis.
-
-@kindex set os
-Use the @code{set os} command to set the operating system. This tells
-@value{GDBN} which kernel object display module to initialize:
-
-@smallexample
-(@value{GDBP}) set os cisco
-@end smallexample
-
-@kindex show os
-The associated command @code{show os} displays the operating system
-set with the @code{set os} command; if no operating system has been
-set, @code{show os} will display an empty string @samp{""}.
-
-If @code{set os} succeeds, @value{GDBN} will display some information
-about the operating system, and will create a new @code{info} command
-which can be used to query the target. The @code{info} command is named
-after the operating system:
-
-@kindex info cisco
-@smallexample
-(@value{GDBP}) info cisco
-List of Cisco Kernel Objects
-Object Description
-any Any and all objects
-@end smallexample
-
-Further subcommands can be used to query about particular objects known
-by the kernel.
-
-There is currently no way to determine whether a given operating
-system is supported other than to try setting it with @kbd{set os
-@var{name}}, where @var{name} is the name of the operating system you
-want to try.
-
-
-@node Remote Debugging
-@chapter Debugging remote programs
-
@menu
* Connecting:: Connecting to a remote target
* Server:: Using the gdbserver program
-* Remote configuration:: Remote configuration
-* remote stub:: Implementing a remote stub
+* Remote Configuration:: Remote configuration
+* Remote Stub:: Implementing a remote stub
@end menu
@node Connecting
-@section Connecting to a remote target
+@section Connecting to a Remote Target
On the @value{GDBN} host machine, you will need an unstripped copy of
-your program, since @value{GDBN} needs symobl and debugging information.
+your program, since @value{GDBN} needs symbol and debugging information.
Start up @value{GDBN} as usual, using the name of the local copy of your
program as the first argument.
If you're using a serial line, you may want to give @value{GDBN} the
@w{@samp{--baud}} option, or use the @code{set remotebaud} command
-(@pxref{Remote configuration, set remotebaud}) before the
+(@pxref{Remote Configuration, set remotebaud}) before the
@code{target} command.
@item target remote @code{@var{host}:@var{port}}
@cindex interrupting remote programs
@cindex remote programs, interrupting
Whenever @value{GDBN} is waiting for the remote program, if you type the
-interrupt character (often @key{C-C}), @value{GDBN} attempts to stop the
+interrupt character (often @kbd{Ctrl-c}), @value{GDBN} attempts to stop the
program. This may or may not succeed, depending in part on the hardware
and the serial drivers the remote system uses. If you type the
interrupt character once again, @value{GDBN} displays this prompt:
@end table
@node Server
-@section Using the @code{gdbserver} program
+@section Using the @code{gdbserver} Program
@kindex gdbserver
@cindex remote connection without stubs
@code{pidof} utility:
@smallexample
-target> gdbserver @var{comm} --attach `pidof @var{PROGRAM}`
+target> gdbserver @var{comm} --attach `pidof @var{program}`
@end smallexample
-In case more than one copy of @var{PROGRAM} is running, or @var{PROGRAM}
+In case more than one copy of @var{program} is running, or @var{program}
has multiple threads, most versions of @code{pidof} support the
@code{-s} option to only return the first process ID.
@item On the host machine,
-connect to your target (@pxref{Connecting,,Connecting to a remote target}).
+first make sure you have the necessary symbol files. Load symbols for
+your application using the @code{file} command before you connect. Use
+@code{set sysroot} to locate target libraries (unless your @value{GDBN}
+was compiled with the correct sysroot using @code{--with-system-root}).
+
+The symbol file and target libraries must exactly match the executable
+and libraries on the target, with one exception: the files on the host
+system should not be stripped, even if the files on the target system
+are. Mismatched or missing files will lead to confusing results
+during debugging. On @sc{gnu}/Linux targets, mismatched or missing
+files may also prevent @code{gdbserver} from debugging multi-threaded
+programs.
+
+Connect to your target (@pxref{Connecting,,Connecting to a Remote Target}).
For TCP connections, you must start up @code{gdbserver} prior to using
the @code{target remote} command. Otherwise you may get an error whose
text depends on the host system, but which usually looks something like
@samp{Connection refused}. You don't need to use the @code{load}
command in @value{GDBN} when using @code{gdbserver}, since the program is
-already on the target. However, if you want to load the symbols (as
-you normally would), do that with the @code{file} command, and issue
-it @emph{before} connecting to the server; otherwise, you will get an
-error message saying @code{"Program is already running"}, since the
-program is considered running after the connection.
+already on the target.
+
+@end table
+
+@subsection Monitor Commands for @code{gdbserver}
+@cindex monitor commands, for @code{gdbserver}
+
+During a @value{GDBN} session using @code{gdbserver}, you can use the
+@code{monitor} command to send special requests to @code{gdbserver}.
+Here are the available commands; they are only of interest when
+debugging @value{GDBN} or @code{gdbserver}.
+
+@table @code
+@item monitor help
+List the available monitor commands.
+
+@item monitor set debug 0
+@itemx monitor set debug 1
+Disable or enable general debugging messages.
+
+@item monitor set remote-debug 0
+@itemx monitor set remote-debug 1
+Disable or enable specific debugging messages associated with the remote
+protocol (@pxref{Remote Protocol}).
@end table
-@node Remote configuration
-@section Remote configuration
+@node Remote Configuration
+@section Remote Configuration
@kindex set remote
@kindex show remote
@table @code
@item set remoteaddresssize @var{bits}
-@cindex adress size for remote targets
+@cindex address size for remote targets
@cindex bits in remote address
Set the maximum size of address in a memory packet to the specified
number of bits. @value{GDBN} will mask off the address bits above
@cindex BREAK signal instead of Ctrl-C
@anchor{set remotebreak}
If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote
-when you press the @key{Ctrl-C} key to interrupt the program running
+when you type @kbd{Ctrl-c} to interrupt the program running
on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C}
character instead. The default is off, since most remote systems
expect to see @samp{Ctrl-C} as the interrupt signal.
Show whether @value{GDBN} sends @code{BREAK} or @samp{Ctrl-C} to
interrupt the remote program.
-@item set remotedevice @var{device}
-@cindex serial port name
-Set the name of the serial port through which to communicate to the
-remote target to @var{device}. This is the device used by
-@value{GDBN} to open the serial communications line to the remote
-target. There's no default, so you must set a valid port name for the
-remote serial communications to work. (Some varieties of the
-@code{target} command accept the port name as part of their
-arguments.)
+@item set remoteflow on
+@itemx set remoteflow off
+@kindex set remoteflow
+Enable or disable hardware flow control (@code{RTS}/@code{CTS})
+on the serial port used to communicate to the remote target.
-@item show remotedevice
-Show the current name of the serial port.
+@item show remoteflow
+@kindex show remoteflow
+Show the current setting of hardware flow control.
@item set remotelogbase @var{base}
Set the base (a.k.a.@: radix) of logging serial protocol
@itemx set remote hardware-breakpoint-limit @var{limit}
Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or
watchpoints. A limit of -1, the default, is treated as unlimited.
+@end table
-@item set remote fetch-register-packet
-@itemx set remote set-register-packet
-@itemx set remote P-packet
-@itemx set remote p-packet
-@cindex P-packet
-@cindex fetch registers from remote targets
-@cindex set registers in remote targets
-Determine whether @value{GDBN} can set and fetch registers from the
-remote target using the @samp{P} packets. The default depends on the
-remote stub's support of the @samp{P} packets (@value{GDBN} queries
-the stub when this packet is first required).
-
-@item show remote fetch-register-packet
-@itemx show remote set-register-packet
-@itemx show remote P-packet
-@itemx show remote p-packet
-Show the current setting of using the @samp{P} packets for setting and
-fetching registers from the remote target.
-
-@cindex binary downloads
-@cindex X-packet
-@item set remote binary-download-packet
-@itemx set remote X-packet
-Determine whether @value{GDBN} sends downloads in binary mode using
-the @samp{X} packets. The default is on.
-
-@item show remote binary-download-packet
-@itemx show remote X-packet
-Show the current setting of using the @samp{X} packets for binary
-downloads.
-
-@item set remote read-aux-vector-packet
-@cindex auxiliary vector of remote target
-@cindex @code{auxv}, and remote targets
-Set the use of the remote protocol's @samp{qPart:auxv:read} (target
-auxiliary vector read) request. This request is used to fetch the
-remote target's @dfn{auxiliary vector}, see @ref{OS Information,
-Auxiliary Vector}. The default setting depends on the remote stub's
-support of this request (@value{GDBN} queries the stub when this
-request is first required). @xref{General Query Packets, qPart}, for
-more information about this request.
-
-@item show remote read-aux-vector-packet
-Show the current setting of use of the @samp{qPart:auxv:read} request.
-
-@item set remote symbol-lookup-packet
-@cindex remote symbol lookup request
-Set the use of the remote protocol's @samp{qSymbol} (target symbol
-lookup) request. This request is used to communicate symbol
-information to the remote target, e.g., whenever a new shared library
-is loaded by the remote (@pxref{Files, shared libraries}). The
-default setting depends on the remote stub's support of this request
-(@value{GDBN} queries the stub when this request is first required).
-@xref{General Query Packets, qSymbol}, for more information about this
-request.
+@cindex remote packets, enabling and disabling
+The @value{GDBN} remote protocol autodetects the packets supported by
+your debugging stub. If you need to override the autodetection, you
+can use these commands to enable or disable individual packets. Each
+packet can be set to @samp{on} (the remote target supports this
+packet), @samp{off} (the remote target does not support this packet),
+or @samp{auto} (detect remote target support for this packet). They
+all default to @samp{auto}. For more information about each packet,
+see @ref{Remote Protocol}.
-@item show remote symbol-lookup-packet
-Show the current setting of use of the @samp{qSymbol} request.
-
-@item set remote verbose-resume-packet
-@cindex resume remote target
-@cindex signal thread, and remote targets
-@cindex single-step thread, and remote targets
-@cindex thread-specific operations on remote targets
-Set the use of the remote protocol's @samp{vCont} (descriptive resume)
-request. This request is used to resume specific threads in the
-remote target, and to single-step or signal them. The default setting
-depends on the remote stub's support of this request (@value{GDBN}
-queries the stub when this request is first required). This setting
-affects debugging of multithreaded programs: if @samp{vCont} cannot be
-used, @value{GDBN} might be unable to single-step a specific thread,
-especially under @code{set scheduler-locking off}; it is also
-impossible to pause a specific thread. @xref{Packets, vCont}, for
-more details.
-
-@item show remote verbose-resume-packet
-Show the current setting of use of the @samp{vCont} request
-
-@item set remote software-breakpoint-packet
-@itemx set remote hardware-breakpoint-packet
-@itemx set remote write-watchpoint-packet
-@itemx set remote read-watchpoint-packet
-@itemx set remote access-watchpoint-packet
-@itemx set remote Z-packet
-@cindex Z-packet
-@cindex remote hardware breakpoints and watchpoints
-These commands enable or disable the use of @samp{Z} packets for
-setting breakpoints and watchpoints in the remote target. The default
-depends on the remote stub's support of the @samp{Z} packets
-(@value{GDBN} queries the stub when each packet is first required).
-The command @code{set remote Z-packet}, kept for back-compatibility,
-turns on or off all the features that require the use of @samp{Z}
-packets.
-
-@item show remote software-breakpoint-packet
-@itemx show remote hardware-breakpoint-packet
-@itemx show remote write-watchpoint-packet
-@itemx show remote read-watchpoint-packet
-@itemx show remote access-watchpoint-packet
-@itemx show remote Z-packet
-Show the current setting of @samp{Z} packets usage.
-
-@item set remote get-thread-local-storage-address
-@kindex set remote get-thread-local-storage-address
-@cindex thread local storage of remote targets
-This command enables or disables the use of the @samp{qGetTLSAddr}
-(Get Thread Local Storage Address) request packet. The default
-depends on whether the remote stub supports this request.
-@xref{General Query Packets, qGetTLSAddr}, for more details about this
-packet.
+During normal use, you should not have to use any of these commands.
+If you do, that may be a bug in your remote debugging stub, or a bug
+in @value{GDBN}. You may want to report the problem to the
+@value{GDBN} developers.
-@item show remote get-thread-local-storage-address
-@kindex show remote get-thread-local-storage-address
-Show the current setting of @samp{qGetTLSAddr} packet usage.
+For each packet @var{name}, the command to enable or disable the
+packet is @code{set remote @var{name}-packet}. The available settings
+are:
-@item set remote supported-packets
-@kindex set remote supported-packets
-@cindex query supported packets of remote targets
-This command enables or disables the use of the @samp{qSupported}
-request packet. @xref{General Query Packets, qSupported}, for more
-details about this packet. The default is to use @samp{qSupported}.
+@multitable @columnfractions 0.28 0.32 0.25
+@item Command Name
+@tab Remote Packet
+@tab Related Features
-@item show remote supported-packets
-@kindex show remote supported-packets
-Show the current setting of @samp{qSupported} packet usage.
-@end table
+@item @code{fetch-register}
+@tab @code{p}
+@tab @code{info registers}
-@node remote stub
-@section Implementing a remote stub
+@item @code{set-register}
+@tab @code{P}
+@tab @code{set}
+
+@item @code{binary-download}
+@tab @code{X}
+@tab @code{load}, @code{set}
+
+@item @code{read-aux-vector}
+@tab @code{qXfer:auxv:read}
+@tab @code{info auxv}
+
+@item @code{symbol-lookup}
+@tab @code{qSymbol}
+@tab Detecting multiple threads
+
+@item @code{verbose-resume}
+@tab @code{vCont}
+@tab Stepping or resuming multiple threads
+
+@item @code{software-breakpoint}
+@tab @code{Z0}
+@tab @code{break}
+
+@item @code{hardware-breakpoint}
+@tab @code{Z1}
+@tab @code{hbreak}
+
+@item @code{write-watchpoint}
+@tab @code{Z2}
+@tab @code{watch}
+
+@item @code{read-watchpoint}
+@tab @code{Z3}
+@tab @code{rwatch}
+
+@item @code{access-watchpoint}
+@tab @code{Z4}
+@tab @code{awatch}
+
+@item @code{target-features}
+@tab @code{qXfer:features:read}
+@tab @code{set architecture}
+
+@item @code{library-info}
+@tab @code{qXfer:libraries:read}
+@tab @code{info sharedlibrary}
+
+@item @code{memory-map}
+@tab @code{qXfer:memory-map:read}
+@tab @code{info mem}
+
+@item @code{read-spu-object}
+@tab @code{qXfer:spu:read}
+@tab @code{info spu}
+
+@item @code{write-spu-object}
+@tab @code{qXfer:spu:write}
+@tab @code{info spu}
+
+@item @code{get-thread-local-@*storage-address}
+@tab @code{qGetTLSAddr}
+@tab Displaying @code{__thread} variables
+
+@item @code{supported-packets}
+@tab @code{qSupported}
+@tab Remote communications parameters
+
+@item @code{pass-signals}
+@tab @code{QPassSignals}
+@tab @code{handle @var{signal}}
+
+@end multitable
+
+@node Remote Stub
+@section Implementing a Remote Stub
@cindex debugging stub, example
@cindex remote stub, example
On certain remote targets, you can use an auxiliary program
@code{gdbserver} instead of linking a stub into your program.
-@xref{Server,,Using the @code{gdbserver} program}, for details.
+@xref{Server,,Using the @code{gdbserver} Program}, for details.
@end table
The debugging stub is specific to the architecture of the remote
@end menu
@node Stub Contents
-@subsection What the stub can do for you
+@subsection What the Stub Can Do for You
@cindex remote serial stub
The debugging stub for your architecture supplies these three
@end table
@node Bootstrapping
-@subsection What you must do for the stub
+@subsection What You Must Do for the Stub
@cindex remote stub, support routines
The debugging stubs that come with @value{GDBN} are set up for a particular
If you do not use the GNU C compiler, you may need other standard
library subroutines as well; this varies from one stub to another,
but in general the stubs are likely to use any of the common library
-subroutines which @code{@value{GCC}} generates as inline code.
+subroutines which @code{@value{NGCC}} generates as inline code.
@node Debug Session
-@subsection Putting it all together
+@subsection Putting it All Together
@cindex remote serial debugging summary
In summary, when your program is ready to debug, you must follow these
@enumerate
@item
Make sure you have defined the supporting low-level routines
-(@pxref{Bootstrapping,,What you must do for the stub}):
+(@pxref{Bootstrapping,,What You Must Do for the Stub}):
@display
@code{getDebugChar}, @code{putDebugChar},
@code{flush_i_cache}, @code{memset}, @code{exceptionHandler}.
@item
Start @value{GDBN} on the host, and connect to the target
-(@pxref{Connecting,,Connecting to a remote target}).
+(@pxref{Connecting,,Connecting to a Remote Target}).
@end enumerate
@end table
@node SVR4 Process Information
-@subsection SVR4 process information
+@subsection SVR4 Process Information
@cindex /proc
@cindex examine process image
@cindex process info via @file{/proc}
@node Cygwin Native
-@subsection Features for Debugging MS Windows PE executables
+@subsection Features for Debugging MS Windows PE Executables
@cindex MS Windows debugging
@cindex native Cygwin debugging
@cindex Cygwin-specific commands
@value{GDBN} supports native debugging of MS Windows programs, including
-DLLs with and without symbolic debugging information. There are various
-additional Cygwin-specific commands, described in this subsection. The
-subsubsection @pxref{Non-debug DLL symbols} describes working with DLLs
-that have no debugging symbols.
-
+DLLs with and without symbolic debugging information. There are various
+additional Cygwin-specific commands, described in this section.
+Working with DLLs that have no debugging symbols is described in
+@ref{Non-debug DLL Symbols}.
@table @code
@kindex info w32
@item info w32
-This is a prefix of MS Windows specific commands which print
+This is a prefix of MS Windows-specific commands which print
information about the target system and important OS structures.
@item info w32 selector
It takes an optional argument that is evaluated to
a long value to give the information about this given selector.
Without argument, this command displays information
-about the the six segment registers.
+about the six segment registers.
@kindex info dll
@item info dll
-This is a Cygwin specific alias of info shared.
+This is a Cygwin-specific alias of @code{info shared}.
@kindex dll-symbols
@item dll-symbols
This boolean value controls whether the debuggee should
start a new group or stay in the same group as the debugger.
This affects the way the Windows OS handles
-Ctrl-C.
+@samp{Ctrl-C}.
@kindex show new-group
@item show new-group
@end table
@menu
-* Non-debug DLL symbols:: Support for DLLs without debugging symbols
+* Non-debug DLL Symbols:: Support for DLLs without debugging symbols
@end menu
-@node Non-debug DLL symbols
-@subsubsection Support for DLLs without debugging symbols
+@node Non-debug DLL Symbols
+@subsubsection Support for DLLs without Debugging Symbols
@cindex DLLs with no debugging symbols
@cindex Minimal symbols and DLLs
Very often on windows, some of the DLLs that your program relies on do
not include symbolic debugging information (for example,
-@file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging
+@file{kernel32.dll}). When @value{GDBN} doesn't recognize any debugging
symbols in a DLL, it relies on the minimal amount of symbolic
-information contained in the DLL's export table. This subsubsection
+information contained in the DLL's export table. This section
describes working with such symbols, known internally to @value{GDBN} as
``minimal symbols''.
Note that before the debugged program has started execution, no DLLs
-will have been loaded. The easiest way around this problem is simply to
+will have been loaded. The easiest way around this problem is simply to
start the program --- either by setting a breakpoint or letting the
-program run once to completion. It is also possible to force
+program run once to completion. It is also possible to force
@value{GDBN} to load a particular DLL before starting the executable ---
-see the shared library information in @pxref{Files} or the
-@code{dll-symbols} command in @pxref{Cygwin Native}. Currently,
+see the shared library information in @ref{Files}, or the
+@code{dll-symbols} command in @ref{Cygwin Native}. Currently,
explicitly loading symbols from a DLL with no debugging information will
cause the symbol names to be duplicated in @value{GDBN}'s lookup table,
which may adversely affect symbol lookup performance.
-@subsubsection DLL name prefixes
+@subsubsection DLL Name Prefixes
In keeping with the naming conventions used by the Microsoft debugging
tools, DLL export symbols are made available with a prefix based on the
though the file name of the DLL is lower-case, or vice-versa. Since
symbols within @value{GDBN} are @emph{case-sensitive} this may cause
some confusion. If in doubt, try the @code{info functions} and
-@code{info variables} commands or even @code{maint print msymbols} (see
-@pxref{Symbols}). Here's an example:
+@code{info variables} commands or even @code{maint print msymbols}
+(@pxref{Symbols}). Here's an example:
@smallexample
(@value{GDBP}) info function CreateFileA
[etc...]
@end smallexample
-@subsubsection Working with minimal symbols
+@subsubsection Working with Minimal Symbols
Symbols extracted from a DLL's export table do not contain very much
type information. All that @value{GDBN} can do is guess whether a symbol
safe.
@node Hurd Native
-@subsection Commands specific to @sc{gnu} Hurd systems
+@subsection Commands Specific to @sc{gnu} Hurd Systems
@cindex @sc{gnu} Hurd debugging
This subsection describes @value{GDBN} commands specific to the
This command shows the state of current thread suspension.
@item set thread run
-This comamnd sets whether the current thread is allowed to run.
+This command sets whether the current thread is allowed to run.
@item show thread run
Show whether the current thread is allowed to run.
@value{GDBN} then attempts to read the symbol tables of any object modules
loaded into the VxWorks target since it was last booted. @value{GDBN} locates
these files by searching the directories listed in the command search
-path (@pxref{Environment, ,Your program's environment}); if it fails
+path (@pxref{Environment, ,Your Program's Environment}); if it fails
to find an object file, it displays a message such as:
@smallexample
command again.
@node VxWorks Download
-@subsubsection VxWorks download
+@subsubsection VxWorks Download
@cindex download to VxWorks
If you have connected to the VxWorks target and you want to debug an
table.)
@node VxWorks Attach
-@subsubsection Running tasks
+@subsubsection Running Tasks
@cindex running VxWorks tasks
You can also attach to an existing task using the @code{attach} command as
@menu
* ARM:: ARM RDI
-* H8/300:: Renesas H8/300
-* H8/500:: Renesas H8/500
* M32R/D:: Renesas M32R/D
* M68K:: Motorola M68K
* MIPS Embedded:: MIPS Embedded
* OpenRISC 1000:: OpenRisc 1000
* PA:: HP PA Embedded
-* PowerPC: PowerPC
-* SH:: Renesas SH
+* PowerPC:: PowerPC
* Sparclet:: Tsqware Sparclet
* Sparclite:: Fujitsu Sparclite
-* ST2000:: Tandem ST2000
* Z8000:: Zilog Z8000
* AVR:: Atmel AVR
* CRIS:: CRIS
* Super-H:: Renesas Super-H
-* WinCE:: Windows CE child processes
@end menu
@node ARM
@end table
-@node H8/300
-@subsection Renesas H8/300
-
-@table @code
-
-@kindex target hms@r{, with H8/300}
-@item target hms @var{dev}
-A Renesas SH, H8/300, or H8/500 board, attached via serial line to your host.
-Use special commands @code{device} and @code{speed} to control the serial
-line and the communications speed used.
-
-@kindex target e7000@r{, with H8/300}
-@item target e7000 @var{dev}
-E7000 emulator for Renesas H8 and SH.
-
-@kindex target sh3@r{, with H8/300}
-@kindex target sh3e@r{, with H8/300}
-@item target sh3 @var{dev}
-@itemx target sh3e @var{dev}
-Renesas SH-3 and SH-3E target systems.
-
-@end table
-
-@cindex download to H8/300 or H8/500
-@cindex H8/300 or H8/500 download
-@cindex download to Renesas SH
-@cindex Renesas SH download
-When you select remote debugging to a Renesas SH, H8/300, or H8/500
-board, the @code{load} command downloads your program to the Renesas
-board and also opens it as the current executable target for
-@value{GDBN} on your host (like the @code{file} command).
-
-@value{GDBN} needs to know these things to talk to your
-Renesas SH, H8/300, or H8/500:
-
-@enumerate
-@item
-that you want to use @samp{target hms}, the remote debugging interface
-for Renesas microprocessors, or @samp{target e7000}, the in-circuit
-emulator for the Renesas SH and the Renesas 300H. (@samp{target hms} is
-the default when @value{GDBN} is configured specifically for the Renesas SH,
-H8/300, or H8/500.)
-
-@item
-what serial device connects your host to your Renesas board (the first
-serial device available on your host is the default).
-
-@item
-what speed to use over the serial device.
-@end enumerate
-
-@menu
-* Renesas Boards:: Connecting to Renesas boards.
-* Renesas ICE:: Using the E7000 In-Circuit Emulator.
-* Renesas Special:: Special @value{GDBN} commands for Renesas micros.
-@end menu
-
-@node Renesas Boards
-@subsubsection Connecting to Renesas boards
-
-@c only for Unix hosts
-@kindex device
-@cindex serial device, Renesas micros
-Use the special @code{@value{GDBN}} command @samp{device @var{port}} if you
-need to explicitly set the serial device. The default @var{port} is the
-first available port on your host. This is only necessary on Unix
-hosts, where it is typically something like @file{/dev/ttya}.
-
-@kindex speed
-@cindex serial line speed, Renesas micros
-@code{@value{GDBN}} has another special command to set the communications
-speed: @samp{speed @var{bps}}. This command also is only used from Unix
-hosts; on DOS hosts, set the line speed as usual from outside @value{GDBN} with
-the DOS @code{mode} command (for instance,
-@w{@kbd{mode com2:9600,n,8,1,p}} for a 9600@dmn{bps} connection).
-
-The @samp{device} and @samp{speed} commands are available only when you
-use a Unix host to debug your Renesas microprocessor programs. If you
-use a DOS host,
-@value{GDBN} depends on an auxiliary terminate-and-stay-resident program
-called @code{asynctsr} to communicate with the development board
-through a PC serial port. You must also use the DOS @code{mode} command
-to set up the serial port on the DOS side.
-
-The following sample session illustrates the steps needed to start a
-program under @value{GDBN} control on an H8/300. The example uses a
-sample H8/300 program called @file{t.x}. The procedure is the same for
-the Renesas SH and the H8/500.
-
-First hook up your development board. In this example, we use a
-board attached to serial port @code{COM2}; if you use a different serial
-port, substitute its name in the argument of the @code{mode} command.
-When you call @code{asynctsr}, the auxiliary comms program used by the
-debugger, you give it just the numeric part of the serial port's name;
-for example, @samp{asyncstr 2} below runs @code{asyncstr} on
-@code{COM2}.
-
-@smallexample
-C:\H8300\TEST> asynctsr 2
-C:\H8300\TEST> mode com2:9600,n,8,1,p
-
-Resident portion of MODE loaded
-
-COM2: 9600, n, 8, 1, p
-
-@end smallexample
-
-@quotation
-@emph{Warning:} We have noticed a bug in PC-NFS that conflicts with
-@code{asynctsr}. If you also run PC-NFS on your DOS host, you may need to
-disable it, or even boot without it, to use @code{asynctsr} to control
-your development board.
-@end quotation
-
-@kindex target hms@r{, and serial protocol}
-Now that serial communications are set up, and the development board is
-connected, you can start up @value{GDBN}. Call @code{@value{GDBN}} with
-the name of your program as the argument. @code{@value{GDBN}} prompts
-you, as usual, with the prompt @samp{(@value{GDBP})}. Use two special
-commands to begin your debugging session: @samp{target hms} to specify
-cross-debugging to the Renesas board, and the @code{load} command to
-download your program to the board. @code{load} displays the names of
-the program's sections, and a @samp{*} for each 2K of data downloaded.
-(If you want to refresh @value{GDBN} data on symbols or on the
-executable file without downloading, use the @value{GDBN} commands
-@code{file} or @code{symbol-file}. These commands, and @code{load}
-itself, are described in @ref{Files,,Commands to specify files}.)
-
-@smallexample
-(eg-C:\H8300\TEST) @value{GDBP} t.x
-@value{GDBN} is free software and you are welcome to distribute copies
- of it under certain conditions; type "show copying" to see
- the conditions.
-There is absolutely no warranty for @value{GDBN}; type "show warranty"
-for details.
-@value{GDBN} @value{GDBVN}, Copyright 1992 Free Software Foundation, Inc...
-(@value{GDBP}) target hms
-Connected to remote H8/300 HMS system.
-(@value{GDBP}) load t.x
-.text : 0x8000 .. 0xabde ***********
-.data : 0xabde .. 0xad30 *
-.stack : 0xf000 .. 0xf014 *
-@end smallexample
-
-At this point, you're ready to run or debug your program. From here on,
-you can use all the usual @value{GDBN} commands. The @code{break} command
-sets breakpoints; the @code{run} command starts your program;
-@code{print} or @code{x} display data; the @code{continue} command
-resumes execution after stopping at a breakpoint. You can use the
-@code{help} command at any time to find out more about @value{GDBN} commands.
-
-Remember, however, that @emph{operating system} facilities aren't
-available on your development board; for example, if your program hangs,
-you can't send an interrupt---but you can press the @sc{reset} switch!
-
-Use the @sc{reset} button on the development board
-@itemize @bullet
-@item
-to interrupt your program (don't use @kbd{ctl-C} on the DOS host---it has
-no way to pass an interrupt signal to the development board); and
-
-@item
-to return to the @value{GDBN} command prompt after your program finishes
-normally. The communications protocol provides no other way for @value{GDBN}
-to detect program completion.
-@end itemize
-
-In either case, @value{GDBN} sees the effect of a @sc{reset} on the
-development board as a ``normal exit'' of your program.
-
-@node Renesas ICE
-@subsubsection Using the E7000 in-circuit emulator
-
-@kindex target e7000@r{, with Renesas ICE}
-You can use the E7000 in-circuit emulator to develop code for either the
-Renesas SH or the H8/300H. Use one of these forms of the @samp{target
-e7000} command to connect @value{GDBN} to your E7000:
-
-@table @code
-@item target e7000 @var{port} @var{speed}
-Use this form if your E7000 is connected to a serial port. The
-@var{port} argument identifies what serial port to use (for example,
-@samp{com2}). The third argument is the line speed in bits per second
-(for example, @samp{9600}).
-
-@item target e7000 @var{hostname}
-If your E7000 is installed as a host on a TCP/IP network, you can just
-specify its hostname; @value{GDBN} uses @code{telnet} to connect.
-@end table
-
-The following special commands are available when debugging with the
-Renesas E7000 ICE:
-
-@table @code
-@item e7000 @var{command}
-@kindex e7000
-@cindex send command to E7000 monitor
-This sends the specified @var{command} to the E7000 monitor.
-
-@item ftplogin @var{machine} @var{username} @var{password} @var{dir}
-@kindex ftplogin@r{, E7000}
-This command records information for subsequent interface with the
-E7000 monitor via the FTP protocol: @value{GDBN} will log into the
-named @var{machine} using specified @var{username} and @var{password},
-and then chdir to the named directory @var{dir}.
-
-@item ftpload @var{file}
-@kindex ftpload@r{, E7000}
-This command uses credentials recorded by @code{ftplogin} to fetch and
-load the named @var{file} from the E7000 monitor.
-
-@item drain
-@kindex drain@r{, E7000}
-This command drains any pending text buffers stored on the E7000.
-
-@item set usehardbreakpoints
-@itemx show usehardbreakpoints
-@kindex set usehardbreakpoints@r{, E7000}
-@kindex show usehardbreakpoints@r{, E7000}
-@cindex hardware breakpoints, and E7000
-These commands set and show the use of hardware breakpoints for all
-breakpoints. @xref{Set Breaks, hardware-assisted breakpoint}, for
-more information about using hardware breakpoints selectively.
-@end table
-
-@node Renesas Special
-@subsubsection Special @value{GDBN} commands for Renesas micros
-
-Some @value{GDBN} commands are available only for the H8/300:
-
-@table @code
-
-@kindex set machine
-@kindex show machine
-@item set machine h8300
-@itemx set machine h8300h
-Condition @value{GDBN} for one of the two variants of the H8/300
-architecture with @samp{set machine}. You can use @samp{show machine}
-to check which variant is currently in effect.
-
-@end table
-
-@node H8/500
-@subsection H8/500
-
-@table @code
-
-@kindex set memory @var{mod}
-@cindex memory models, H8/500
-@item set memory @var{mod}
-@itemx show memory
-Specify which H8/500 memory model (@var{mod}) you are using with
-@samp{set memory}; check which memory model is in effect with @samp{show
-memory}. The accepted values for @var{mod} are @code{small},
-@code{big}, @code{medium}, and @code{compact}.
-
-@end table
-
@node M32R/D
@subsection Renesas M32R/D and M32R/SDI
@item set download-path @var{path}
@kindex set download-path
@cindex find downloadable @sc{srec} files (M32R)
-Set the default path for finding donwloadable @sc{srec} files.
+Set the default path for finding downloadable @sc{srec} files.
@item show download-path
@kindex show download-path
@node M68K
@subsection M68k
-The Motorola m68k configuration includes ColdFire support, and
-target command for the following ROM monitors.
+The Motorola m68k configuration includes ColdFire support, and a
+target command for the following ROM monitor.
@table @code
-@kindex target abug
-@item target abug @var{dev}
-ABug ROM monitor for M68K.
-
-@kindex target cpu32bug
-@item target cpu32bug @var{dev}
-CPU32BUG monitor, running on a CPU32 (M68K) board.
-
@kindex target dbug
@item target dbug @var{dev}
dBUG ROM monitor for Motorola ColdFire.
-@kindex target est
-@item target est @var{dev}
-EST-300 ICE monitor, running on a CPU32 (M68K) board.
-
-@kindex target rom68k
-@item target rom68k @var{dev}
-ROM 68K monitor, running on an M68K IDP board.
-
@end table
-@table @code
-
-@kindex target rombug
-@item target rombug @var{dev}
-ROMBUG ROM monitor for OS/9000.
-
-@end table
-
-@node MIPS Embedded
-@subsection MIPS Embedded
+@node MIPS Embedded
+@subsection MIPS Embedded
@cindex MIPS boards
@value{GDBN} can use the MIPS remote debugging protocol to talk to a
@table @code
@kindex hwatch
@item hwatch @var{conditional}
-Set hardware watchpoint on combination of Load/Store Effecive Address(es)
+Set hardware watchpoint on combination of Load/Store Effective Address(es)
or Data. For example:
@code{hwatch ($LEA == my_var) && ($LDATA < 50) || ($SEA == my_var) && ($SDATA >= 50)}
@end table
@cindex SDS protocol
-The following commands specifi to the SDS protocol are supported
+The following commands specific to the SDS protocol are supported
by@value{GDBN}:
@table @code
@end table
-@node SH
-@subsection Renesas SH
-
-@table @code
-
-@kindex target hms@r{, with Renesas SH}
-@item target hms @var{dev}
-A Renesas SH board attached via serial line to your host. Use special
-commands @code{device} and @code{speed} to control the serial line and
-the communications speed used.
-
-@kindex target e7000@r{, with Renesas SH}
-@item target e7000 @var{dev}
-E7000 emulator for Renesas SH.
-
-@kindex target sh3@r{, with SH}
-@kindex target sh3e@r{, with SH}
-@item target sh3 @var{dev}
-@item target sh3e @var{dev}
-Renesas SH-3 and SH-3E target systems.
-
-@end table
-
@node Sparclet
@subsection Tsqware Sparclet
@end menu
@node Sparclet File
-@subsubsection Setting file to debug
+@subsubsection Setting File to Debug
The @value{GDBN} command @code{file} lets you choose with program to debug.
@value{GDBN} locates
the file by searching the directories listed in the command search
path.
-If the file was compiled with debug information (option "-g"), source
+If the file was compiled with debug information (option @samp{-g}), source
files will be searched as well.
@value{GDBN} locates
the source files by searching the directories listed in the directory search
-path (@pxref{Environment, ,Your program's environment}).
+path (@pxref{Environment, ,Your Program's Environment}).
If it fails
to find a file, it displays a message such as:
@end smallexample
@node Sparclet Download
-@subsubsection Sparclet download
+@subsubsection Sparclet Download
@cindex download to Sparclet
Once connected to the Sparclet target,
to tell @value{GDBN} where to map the symbol table.
@node Sparclet Execution
-@subsubsection Running and debugging
+@subsubsection Running and Debugging
@cindex running and debugging Sparclet programs
You can now begin debugging the task using @value{GDBN}'s execution control
@end table
-@node ST2000
-@subsection Tandem ST2000
-
-@value{GDBN} may be used with a Tandem ST2000 phone switch, running Tandem's
-STDBUG protocol.
-
-To connect your ST2000 to the host system, see the manufacturer's
-manual. Once the ST2000 is physically attached, you can run:
-
-@smallexample
-target st2000 @var{dev} @var{speed}
-@end smallexample
-
-@noindent
-to establish it as your debugging environment. @var{dev} is normally
-the name of a serial device, such as @file{/dev/ttya}, connected to the
-ST2000 via a serial line. You can instead specify @var{dev} as a TCP
-connection (for example, to a serial line attached via a terminal
-concentrator) using the syntax @code{@var{hostname}:@var{portnumber}}.
-
-The @code{load} and @code{attach} commands are @emph{not} defined for
-this target; you must load your program into the ST2000 as you normally
-would for standalone operation. @value{GDBN} reads debugging information
-(such as symbols) from a separate, debugging version of the program
-available on your host computer.
-@c FIXME!! This is terribly vague; what little content is here is
-@c basically hearsay.
-
-@cindex ST2000 auxiliary commands
-These auxiliary @value{GDBN} commands are available to help you with the ST2000
-environment:
-
-@table @code
-@item st2000 @var{command}
-@kindex st2000 @var{cmd}
-@cindex STDBUG commands (ST2000)
-@cindex commands to STDBUG (ST2000)
-Send a @var{command} to the STDBUG monitor. See the manufacturer's
-manual for available commands.
-
-@item connect
-@cindex connect (to STDBUG)
-Connect the controlling terminal to the STDBUG command monitor. When
-you are done interacting with STDBUG, typing either of two character
-sequences gets you back to the @value{GDBN} command prompt:
-@kbd{@key{RET}~.} (Return, followed by tilde and period) or
-@kbd{@key{RET}~@key{C-d}} (Return, followed by tilde and control-D).
-@end table
-
@node Z8000
@subsection Zilog Z8000
Show the values of all Super-H registers.
@end table
-@node WinCE
-@subsection Windows CE
-@cindex Windows CE
-
-The following commands are available for Windows CE:
-
-@table @code
-@item set remotedirectory @var{dir}
-@kindex set remotedirectory
-Tell @value{GDBN} to upload files from the named directory @var{dir}.
-The default is @file{/gdb}, i.e.@: the root directory on the current
-drive.
-
-@item show remotedirectory
-@kindex show remotedirectory
-Show the current value of the upload directory.
-
-@item set remoteupload @var{method}
-@kindex set remoteupload
-Set the method used to upload files to remote device. Valid values
-for @var{method} are @samp{always}, @samp{newer}, and @samp{never}.
-The default is @samp{newer}.
-
-@item show remoteupload
-@kindex show remoteupload
-Show the current setting of the upload method.
-
-@item set remoteaddhost
-@kindex set remoteaddhost
-Tell @value{GDBN} whether to add this host to the remote stub's
-arguments when you debug over a network.
-
-@item show remoteaddhost
-@kindex show remoteaddhost
-Show whether to add this host to remote stub's arguments when
-debugging over a network.
-@end table
-
@node Architectures
@section Architectures
* Alpha::
* MIPS::
* HPPA:: HP PA architecture
+* SPU:: Cell Broadband Engine SPU architecture
@end menu
@node i386
-@subsection x86 Architecture-specific issues.
+@subsection x86 Architecture-specific Issues
@table @code
@item set struct-convention @var{mode}
programs:
@table @code
-@item set mips saved-gpreg-size @var{size}
-@kindex set mips saved-gpreg-size
-@cindex MIPS GP register size on stack
-Set the size of MIPS general-purpose registers saved on the stack.
-The argument @var{size} can be one of the following:
-
-@table @samp
-@item 32
-32-bit GP registers
-@item 64
-64-bit GP registers
-@item auto
-Use the target's default setting or autodetect the saved size from the
-information contained in the executable. This is the default
-@end table
-
-@item show mips saved-gpreg-size
-@kindex show mips saved-gpreg-size
-Show the current size of MIPS GP registers on the stack.
-
-@item set mips stack-arg-size @var{size}
-@kindex set mips stack-arg-size
-@cindex MIPS stack space for arguments
-Set the amount of stack space reserved for arguments to functions.
-The argument can be one of @code{"32"}, @code{"64"} or @code{"auto"}
-(the default).
-
@item set mips abi @var{arg}
@kindex set mips abi
@cindex set ABI for MIPS
@subsection HPPA
@cindex HPPA support
-When @value{GDBN} is debugging te HP PA architecture, it provides the
+When @value{GDBN} is debugging the HP PA architecture, it provides the
following special commands:
@table @code
@item set debug hppa
@kindex set debug hppa
-THis command determines whether HPPA architecture specific debugging
+This command determines whether HPPA architecture-specific debugging
messages are to be displayed.
@item show debug hppa
@end table
+@node SPU
+@subsection Cell Broadband Engine SPU architecture
+@cindex Cell Broadband Engine
+@cindex SPU
+
+When @value{GDBN} is debugging the Cell Broadband Engine SPU architecture,
+it provides the following special commands:
+
+@table @code
+@item info spu event
+@kindex info spu
+Display SPU event facility status. Shows current event mask
+and pending event status.
+
+@item info spu signal
+Display SPU signal notification facility status. Shows pending
+signal-control word and signal notification mode of both signal
+notification channels.
+
+@item info spu mailbox
+Display SPU mailbox facility status. Shows all pending entries,
+in order of processing, in each of the SPU Write Outbound,
+SPU Write Outbound Interrupt, and SPU Read Inbound mailboxes.
+
+@item info spu dma
+Display MFC DMA status. Shows all pending commands in the MFC
+DMA queue. For each entry, opcode, tag, class IDs, effective
+and local store addresses and transfer size are shown.
+
+@item info spu proxydma
+Display MFC Proxy-DMA status. Shows all pending commands in the MFC
+Proxy-DMA queue. For each entry, opcode, tag, class IDs, effective
+and local store addresses and transfer size are shown.
+
+@end table
+
+
@node Controlling GDB
@chapter Controlling @value{GDBN}
You can alter the way @value{GDBN} interacts with you by using the
@code{set} command. For commands controlling how @value{GDBN} displays
-data, see @ref{Print Settings, ,Print settings}. Other settings are
+data, see @ref{Print Settings, ,Print Settings}. Other settings are
described here.
@menu
@end table
@node Editing
-@section Command editing
+@section Command Editing
@cindex readline
@cindex command line editing
encouraged to read that chapter.
@node Command History
-@section Command history
+@section Command History
@cindex command history
@value{GDBN} can keep track of the commands you type during your
Interactively}, for the detailed description of the History library.
To issue a command to @value{GDBN} without affecting certain aspects of
-the state which is seen by users, prefix it with @samp{server }. This
+the state which is seen by users, prefix it with @samp{server }
+(@pxref{Server Prefix}). This
means that this command will not affect the command history, nor will it
affect @value{GDBN}'s notion of which command to repeat if @key{RET} is
pressed on a line by itself.
@end table
@node Screen Size
-@section Screen size
+@section Screen Size
@cindex size of screen
@cindex pauses in output
@end table
@node ABI
-@section Configuring the current ABI
+@section Configuring the Current ABI
@value{GDBN} can determine the @dfn{ABI} (Application Binary Interface) of your
application automatically. However, sometimes you need to override its
@end table
@node Messages/Warnings
-@section Optional warnings and messages
+@section Optional Warnings and Messages
@cindex verbose operation
@cindex optional warnings
Currently, the messages controlled by @code{set verbose} are those
which announce that the symbol table for a source file is being read;
-see @code{symbol-file} in @ref{Files, ,Commands to specify files}.
+see @code{symbol-file} in @ref{Files, ,Commands to Specify Files}.
@table @code
@kindex set verbose
By default, if @value{GDBN} encounters bugs in the symbol table of an
object file, it is silent; but if you are debugging a compiler, you may
-find this information useful (@pxref{Symbol Errors, ,Errors reading
-symbol files}).
+find this information useful (@pxref{Symbol Errors, ,Errors Reading
+Symbol Files}).
@table @code
@end table
+@cindex command tracing
+If you need to debug user-defined commands or sourced files you may find it
+useful to enable @dfn{command tracing}. In this mode each command will be
+printed as it is executed, prefixed with one or more @samp{+} symbols, the
+quantity denoting the call depth of each command.
+
+@table @code
+@kindex set trace-commands
+@cindex command scripts, debugging
+@item set trace-commands on
+Enable command tracing.
+@item set trace-commands off
+Disable command tracing.
+@item show trace-commands
+Display the current state of command tracing.
+@end table
+
@node Debugging Output
-@section Optional messages about internal happenings
+@section Optional Messages about Internal Happenings
@cindex optional debugging messages
@value{GDBN} has commands that enable optional debugging messages from
@item show debugvarobj
Displays the current state of displaying @value{GDBN} variable object
debugging info.
+@item set debug xml
+@cindex XML parser debugging
+Turns on or off debugging messages for built-in XML parsers.
+@item show debug xml
+Displays the current state of XML debugging messages.
@end table
@node Sequences
@chapter Canned Sequences of Commands
Aside from breakpoint commands (@pxref{Break Commands, ,Breakpoint
-command lists}), @value{GDBN} provides two ways to store sequences of
+Command Lists}), @value{GDBN} provides two ways to store sequences of
commands for execution as a unit: user-defined commands and command
files.
@end menu
@node Define
-@section User-defined commands
+@section User-defined Commands
@cindex user-defined command
@cindex arguments, to user-defined commands
@item show max-user-call-depth
@itemx set max-user-call-depth
The value of @code{max-user-call-depth} controls how many recursion
-levels are allowed in user-defined commands before GDB suspects an
+levels are allowed in user-defined commands before @value{GDBN} suspects an
infinite recursion and aborts the command.
@end table
messages when used in a user-defined command.
@node Hooks
-@section User-defined command hooks
+@section User-defined Command Hooks
@cindex command hooks
@cindex hooks, for commands
@cindex hooks, pre-command
end
define hook-continue
-handle SIGLARM pass
+handle SIGALRM pass
end
@end smallexample
-As a further example, to hook at the begining and end of the @code{echo}
+As a further example, to hook at the beginning and end of the @code{echo}
command, and to add extra text to the beginning and end of the message,
you could define:
get a warning from the @code{define} command.
@node Command Files
-@section Command files
+@section Command Files
@cindex command files
@cindex scripting commands
@table @code
@kindex source
@cindex execute commands from a file
-@item source @var{filename}
+@item source [@code{-v}] @var{filename}
Execute the command file @var{filename}.
@end table
@value{GDBN} searches for @var{filename} in the current directory and then
on the search path (specified with the @samp{directory} command).
+If @code{-v}, for verbose mode, is given then @value{GDBN} displays
+each command as it is executed. The option must be given before
+@var{filename}, and is interpreted as part of the filename anywhere else.
+
Commands that would ask for confirmation if used interactively proceed
without asking when used in a command file. Many @value{GDBN} commands that
normally print messages to say what they are doing omit the messages
@node Output
-@section Commands for controlled output
+@section Commands for Controlled Output
During the execution of a command file or a user-defined command, normal
@value{GDBN} output is suppressed; the only output that appears is what is
@item output/@var{fmt} @var{expression}
Print the value of @var{expression} in format @var{fmt}. You can use
the same formats as for @code{print}. @xref{Output Formats,,Output
-formats}, for more information.
+Formats}, for more information.
@kindex printf
@item printf @var{string}, @var{expressions}@dots{}
* TUI Overview:: TUI overview
* TUI Keys:: TUI key bindings
* TUI Single Key Mode:: TUI single key mode
-* TUI Commands:: TUI specific commands
+* TUI Commands:: TUI-specific commands
* TUI Configuration:: TUI configuration variables
@end menu
-The @value{GDBN} Text User Interface, TUI in short, is a terminal
+The @value{GDBN} Text User Interface (TUI) is a terminal
interface which uses the @code{curses} library to show the source
file, the assembly output, the program registers and @value{GDBN}
-commands in separate text windows.
+commands in separate text windows. The TUI mode is supported only
+on platforms where a suitable version of the @code{curses} library
+is available.
-The TUI is enabled by invoking @value{GDBN} using either
-@pindex gdbtui
-@samp{gdbtui} or @samp{gdb -tui}.
+@pindex @value{GDBTUI}
+The TUI mode is enabled by default when you invoke @value{GDBN} as
+either @samp{@value{GDBTUI}} or @samp{@value{GDBP} -tui}.
+You can also switch in and out of TUI mode while @value{GDBN} runs by
+using various TUI commands and key bindings, such as @kbd{C-x C-a}.
+@xref{TUI Keys, ,TUI Key Bindings}.
@node TUI Overview
-@section TUI overview
-
-The TUI has two display modes that can be switched while
-@value{GDBN} runs:
-
-@itemize @bullet
-@item
-A curses (or TUI) mode in which it displays several text
-windows on the terminal.
+@section TUI Overview
-@item
-A standard mode which corresponds to the @value{GDBN} configured without
-the TUI.
-@end itemize
-
-In the TUI mode, @value{GDBN} can display several text window
-on the terminal:
+In TUI mode, @value{GDBN} can display several text windows:
@table @emph
@item command
This window is the @value{GDBN} command window with the @value{GDBN}
-prompt and the @value{GDBN} outputs. The @value{GDBN} input is still
-managed using readline but through the TUI. The @emph{command}
-window is always visible.
+prompt and the @value{GDBN} output. The @value{GDBN} input is still
+managed using readline.
@item source
The source window shows the source file of the program. The current
-line as well as active breakpoints are displayed in this window.
+line and active breakpoints are displayed in this window.
@item assembly
The assembly window shows the disassembly output of the program.
@item register
-This window shows the processor registers. It detects when
-a register is changed and when this is the case, registers that have
-changed are highlighted.
-
+This window shows the processor registers. Registers are highlighted
+when their values change.
@end table
The source and assembly windows show the current program position
-by highlighting the current line and marking them with the @samp{>} marker.
-Breakpoints are also indicated with two markers. A first one
+by highlighting the current line and marking it with a @samp{>} marker.
+Breakpoints are indicated with two markers. The first marker
indicates the breakpoint type:
@table @code
@item h
Hardware breakpoint which was never hit.
-
@end table
The second marker indicates whether the breakpoint is enabled or not:
@item -
Breakpoint is disabled.
-
@end table
-The source, assembly and register windows are attached to the thread
-and the frame position. They are updated when the current thread
-changes, when the frame changes or when the program counter changes.
-These three windows are arranged by the TUI according to several
-layouts. The layout defines which of these three windows are visible.
-The following layouts are available:
+The source, assembly and register windows are updated when the current
+thread changes, when the frame changes, or when the program counter
+changes.
+
+These windows are not all visible at the same time. The command
+window is always visible. The others can be arranged in several
+layouts:
@itemize @bullet
@item
-source
+source only,
@item
-assembly
+assembly only,
@item
-source and assembly
+source and assembly,
@item
-source and registers
+source and registers, or
@item
-assembly and registers
-
+assembly and registers.
@end itemize
-On top of the command window a status line gives various information
-concerning the current process begin debugged. The status line is
-updated when the information it shows changes. The following fields
-are displayed:
+A status line above the command window shows the following information:
@table @emph
@item target
-Indicates the current gdb target
+Indicates the current @value{GDBN} target.
(@pxref{Targets, ,Specifying a Debugging Target}).
@item process
-Gives information about the current process or thread number.
+Gives the current process or thread number.
When no process is being debugged, this field is set to @code{No process}.
@item function
Gives the current function name for the selected frame.
The name is demangled if demangling is turned on (@pxref{Print Settings}).
-When there is no symbol corresponding to the current program counter
+When there is no symbol corresponding to the current program counter,
the string @code{??} is displayed.
@item line
Indicates the current line number for the selected frame.
-When the current line number is not known the string @code{??} is displayed.
+When the current line number is not known, the string @code{??} is displayed.
@item pc
Indicates the current program counter address.
-
@end table
@node TUI Keys
@cindex TUI key bindings
The TUI installs several key bindings in the readline keymaps
-(@pxref{Command Line Editing}).
-They allow to leave or enter in the TUI mode or they operate
-directly on the TUI layout and windows. The TUI also provides
-a @emph{SingleKey} keymap which binds several keys directly to
-@value{GDBN} commands. The following key bindings
+(@pxref{Command Line Editing}). The following key bindings
are installed for both TUI mode and the @value{GDBN} standard mode.
@table @kbd
@itemx C-x a
@kindex C-x A
@itemx C-x A
-Enter or leave the TUI mode. When the TUI mode is left,
-the curses window management is left and @value{GDBN} operates using
-its standard mode writing on the terminal directly. When the TUI
-mode is entered, the control is given back to the curses windows.
+Enter or leave the TUI mode. When leaving the TUI mode,
+the curses window management stops and @value{GDBN} operates using
+its standard mode, writing on the terminal directly. When reentering
+the TUI mode, control is given back to the curses windows.
The screen is then refreshed.
@kindex C-x 1
@kindex C-x 2
@item C-x 2
Use a TUI layout with at least two windows. When the current
-layout shows already two windows, a next layout with two windows is used.
+layout already has two windows, the next layout with two windows is used.
When a new layout is chosen, one window will always be common to the
previous layout and the new one.
@kindex C-x o
@item C-x o
Change the active window. The TUI associates several key bindings
-(like scrolling and arrow keys) to the active window. This command
+(like scrolling and arrow keys) with the active window. This command
gives the focus to the next TUI window.
Think of it as the Emacs @kbd{C-x o} binding.
@kindex C-x s
@item C-x s
-Use the TUI @emph{SingleKey} keymap that binds single key to gdb commands
-(@pxref{TUI Single Key Mode}).
-
+Switch in and out of the TUI SingleKey mode that binds single
+keys to @value{GDBN} commands (@pxref{TUI Single Key Mode}).
@end table
-The following key bindings are handled only by the TUI mode:
+The following key bindings only work in the TUI mode:
-@table @key
+@table @asis
@kindex PgUp
-@item PgUp
+@item @key{PgUp}
Scroll the active window one page up.
@kindex PgDn
-@item PgDn
+@item @key{PgDn}
Scroll the active window one page down.
@kindex Up
-@item Up
+@item @key{Up}
Scroll the active window one line up.
@kindex Down
-@item Down
+@item @key{Down}
Scroll the active window one line down.
@kindex Left
-@item Left
+@item @key{Left}
Scroll the active window one column left.
@kindex Right
-@item Right
+@item @key{Right}
Scroll the active window one column right.
@kindex C-L
-@item C-L
+@item @kbd{C-L}
Refresh the screen.
-
@end table
-In the TUI mode, the arrow keys are used by the active window
-for scrolling. This means they are available for readline when the
-active window is the command window. When the command window
-does not have the focus, it is necessary to use other readline
-key bindings such as @key{C-p}, @key{C-n}, @key{C-b} and @key{C-f}.
+Because the arrow keys scroll the active window in the TUI mode, they
+are not available for their normal use by readline unless the command
+window has the focus. When another window is active, you must use
+other readline key bindings such as @kbd{C-p}, @kbd{C-n}, @kbd{C-b}
+and @kbd{C-f} to control the command window.
@node TUI Single Key Mode
@section TUI Single Key Mode
@cindex TUI single key mode
-The TUI provides a @emph{SingleKey} mode in which it installs a particular
-key binding in the readline keymaps to connect single keys to
-some gdb commands.
+The TUI also provides a @dfn{SingleKey} mode, which binds several
+frequently used @value{GDBN} commands to single keys. Type @kbd{C-x s} to
+switch into this mode, where the following key bindings are used:
@table @kbd
@kindex c @r{(SingleKey TUI key)}
@kindex q @r{(SingleKey TUI key)}
@item q
-exit the @emph{SingleKey} mode.
+exit the SingleKey mode.
@kindex r @r{(SingleKey TUI key)}
@item r
@kindex w @r{(SingleKey TUI key)}
@item w
where
-
@end table
Other keys temporarily switch to the @value{GDBN} command prompt.
The key that was pressed is inserted in the editing buffer so that
it is possible to type most @value{GDBN} commands without interaction
-with the TUI @emph{SingleKey} mode. Once the command is entered the TUI
-@emph{SingleKey} mode is restored. The only way to permanently leave
-this mode is by hitting @key{q} or @samp{@key{C-x} @key{s}}.
+with the TUI SingleKey mode. Once the command is entered the TUI
+SingleKey mode is restored. The only way to permanently leave
+this mode is by typing @kbd{q} or @kbd{C-x s}.
@node TUI Commands
-@section TUI specific commands
+@section TUI-specific Commands
@cindex TUI commands
The TUI has specific commands to control the text windows.
-These commands are always available, that is they do not depend on
-the current terminal mode in which @value{GDBN} runs. When @value{GDBN}
-is in the standard mode, using these commands will automatically switch
-in the TUI mode.
+These commands are always available, even when @value{GDBN} is not in
+the TUI mode. When @value{GDBN} is in the standard mode, most
+of these commands will automatically switch to the TUI mode.
@table @code
@item info win
@item layout regs
Display the register window together with the source or assembly window.
-@item focus next | prev | src | asm | regs | split
+@item focus next
@kindex focus
-Set the focus to the named window.
-This command allows to change the active window so that scrolling keys
-can be affected to another window.
+Make the next window active for scrolling.
+
+@item focus prev
+Make the previous window active for scrolling.
+
+@item focus src
+Make the source window active for scrolling.
+
+@item focus asm
+Make the assembly window active for scrolling.
+
+@item focus regs
+Make the register window active for scrolling.
+
+@item focus cmd
+Make the command window active for scrolling.
@item refresh
@kindex refresh
-Refresh the screen. This is similar to using @key{C-L} key.
+Refresh the screen. This is similar to typing @kbd{C-L}.
@item tui reg float
@kindex tui reg
lines. Positive counts increase the height, while negative counts
decrease it.
-@item tabset
-@kindex tabset @var{nchars}
+@item tabset @var{nchars}
+@kindex tabset
Set the width of tab stops to be @var{nchars} characters.
-
@end table
@node TUI Configuration
-@section TUI configuration variables
+@section TUI Configuration Variables
@cindex TUI configuration variables
-The TUI has several configuration variables that control the
-appearance of windows on the terminal.
+Several configuration variables control the appearance of TUI windows.
@table @code
@item set tui border-kind @var{kind}
Use a space character to draw the border.
@item ascii
-Use ascii characters + - and | to draw the border.
+Use @sc{ascii} characters @samp{+}, @samp{-} and @samp{|} to draw the border.
@item acs
Use the Alternate Character Set to draw the border. The border is
drawn using character line graphics if the terminal supports them.
-
@end table
-@item set tui active-border-mode @var{mode}
-@kindex set tui active-border-mode
-Select the attributes to display the border of the active window.
-The possible values are @code{normal}, @code{standout}, @code{reverse},
-@code{half}, @code{half-standout}, @code{bold} and @code{bold-standout}.
-
@item set tui border-mode @var{mode}
@kindex set tui border-mode
-Select the attributes to display the border of other windows.
-The @var{mode} can be one of the following:
+@itemx set tui active-border-mode @var{mode}
+@kindex set tui active-border-mode
+Select the display attributes for the borders of the inactive windows
+or the active window. The @var{mode} can be one of the following:
@table @code
@item normal
Use normal attributes to display the border.
@item bold-standout
Use extra bright or bold and standout mode.
-
@end table
-
@end table
@node Emacs
created Emacs buffer.
@c (Do not use the @code{-tui} option to run @value{GDBN} from Emacs.)
-Using @value{GDBN} under Emacs is just like using @value{GDBN} normally except for two
+Running @value{GDBN} under Emacs can be just like running @value{GDBN} normally except for two
things:
@itemize @bullet
@item
-All ``terminal'' input and output goes through the Emacs buffer.
-@end itemize
+All ``terminal'' input and output goes through an Emacs buffer, called
+the GUD buffer.
This applies both to @value{GDBN} commands and their output, and to the input
and output done by the program you are debugging.
way---for example, @kbd{C-c C-c} for an interrupt, @kbd{C-c C-z} for a
stop.
-@itemize @bullet
@item
@value{GDBN} displays source code through Emacs.
-@end itemize
Each time @value{GDBN} displays a stack frame, Emacs automatically finds the
source file for that frame and puts an arrow (@samp{=>}) at the
Explicit @value{GDBN} @code{list} or search commands still produce output as
usual, but you probably have no reason to use them from Emacs.
+@end itemize
+
+We call this @dfn{text command mode}. Emacs 22.1, and later, also uses
+a graphical mode, enabled by default, which provides further buffers
+that can control the execution and describe the state of your program.
+@xref{GDB Graphical Interface,,, Emacs, The @sc{gnu} Emacs Manual}.
If you specify an absolute file name when prompted for the @kbd{M-x
gdb} argument, then Emacs sets your current working directory to where
buffer does not display the current source and line of execution.
The initial working directory of @value{GDBN} is printed on the top
-line of the @value{GDBN} I/O buffer and this serves as a default for
-the commands that specify files for @value{GDBN} to operate
-on. @xref{Files, ,Commands to specify files}.
+line of the GUD buffer and this serves as a default for the commands
+that specify files for @value{GDBN} to operate on. @xref{Files,
+,Commands to Specify Files}.
By default, @kbd{M-x gdb} calls the program called @file{gdb}. If you
need to call @value{GDBN} by a different name (for example, if you
customize the Emacs variable @code{gud-gdb-command-name} to run the
one you want.
-In the @value{GDBN} I/O buffer, you can use these special Emacs commands in
+In the GUD buffer, you can use these special Emacs commands in
addition to the standard Shell mode commands:
@table @kbd
@item C-h m
-Describe the features of Emacs' @value{GDBN} Mode.
+Describe the features of Emacs' GUD Mode.
@item C-c C-s
Execute to another source line, like the @value{GDBN} @code{step} command; also
@value{GDBN} @code{down} command.
@end table
-In any source file, the Emacs command @kbd{C-x SPC} (@code{gud-break})
+In any source file, the Emacs command @kbd{C-x @key{SPC}} (@code{gud-break})
tells @value{GDBN} to set a breakpoint on the source line point is on.
-If you type @kbd{M-x speedbar}, then Emacs displays a separate frame which
-shows a backtrace when the @value{GDBN} I/O buffer is current. Move
-point to any frame in the stack and type @key{RET} to make it become the
-current frame and display the associated source in the source buffer.
-Alternatively, click @kbd{Mouse-2} to make the selected frame become the
-current one.
+In text command mode, if you type @kbd{M-x speedbar}, Emacs displays a
+separate frame which shows a backtrace when the GUD buffer is current.
+Move point to any frame in the stack and type @key{RET} to make it
+become the current frame and display the associated source in the
+source buffer. Alternatively, click @kbd{Mouse-2} to make the
+selected frame become the current one. In graphical mode, the
+speedbar displays watch expressions.
If you accidentally delete the source-display buffer, an easy way to get
it back is to type the command @code{f} in the @value{GDBN} buffer, to
delete lines from the text, the line numbers that @value{GDBN} knows cease
to correspond properly with the code.
-The description given here is for GNU Emacs version 21.3 and a more
-detailed description of its interaction with @value{GDBN} is given in
-the Emacs manual (@pxref{Debuggers,,, Emacs, The @sc{gnu} Emacs Manual}).
+A more detailed description of Emacs' interaction with @value{GDBN} is
+given in the Emacs manual (@pxref{Debuggers,,, Emacs, The @sc{gnu}
+Emacs Manual}).
@c The following dropped because Epoch is nonstandard. Reactivate
@c if/when v19 does something similar. ---doc@cygnus.com 19dec1990
@item
New fields may be added to the output of any MI command.
+@item
+The range of values for fields with specified values, e.g.,
+@code{in_scope} (@pxref{-var-update}) may be extended.
+
@c The format of field's content e.g type prefix, may change so parse it
@c at your own risk. Yes, in general?
follow development on @email{gdb@@sourceware.org} and
@email{gdb-patches@@sourceware.org}. There is also the mailing list
@email{dmi-discuss@@lists.freestandards.org}, hosted by the Free Standards
-Group, which has the aim of creating a a more general MI protocol
+Group, which has the aim of creating a more general MI protocol
called Debugger Machine Interface (DMI) that will become a standard
for all debuggers, not just @value{GDBN}.
@cindex mailing lists
@item "^connected"
@findex ^connected
-GDB has connected to a remote target.
+@value{GDBN} has connected to a remote target.
@item "^error" "," @var{c-string}
@findex ^error
@item "^exit"
@findex ^exit
-GDB has terminated.
+@value{GDBN} has terminated.
@end table
following line is passed to @sc{gdb/mi} as input, while @samp{<-} means
the output received from @sc{gdb/mi}.
-Note the the line breaks shown in the examples are here only for
+Note the line breaks shown in the examples are here only for
readability, they don't appear in the real output.
-@subheading Setting a breakpoint
+@subheading Setting a Breakpoint
Setting a breakpoint generates synchronous output which contains detailed
information of the breakpoint.
<- (gdb)
@end smallexample
-@subheading Quitting GDB
+@subheading Quitting @value{GDBN}
-Quitting GDB just prints the result class @samp{^exit}.
+Quitting @value{GDBN} just prints the result class @samp{^exit}.
@smallexample
-> (gdb)
Delete the breakpoint(s) whose number(s) are specified in the argument
list. This is obviously reflected in the breakpoint list.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{delete}.
@c REDUNDANT???
Get information about a single breakpoint.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{info break @var{breakpoint}}.
@item -r
Insert a regular breakpoint in all the functions whose names match the
given regular expression. Other flags are not applicable to regular
-expresson.
+expressions.
@end table
@subsubheading Result
@end smallexample
Create a watchpoint. With the @samp{-a} option it will create an
-@dfn{access} watchpoint, i.e. a watchpoint that triggers either on a
+@dfn{access} watchpoint, i.e., a watchpoint that triggers either on a
read from or on a write to the memory location. With the @samp{-r}
-option, the watchpoint created is a @dfn{read} watchpoint, i.e. it will
+option, the watchpoint created is a @dfn{read} watchpoint, i.e., it will
trigger only when the memory location is accessed for reading. Without
either of the options, the watchpoint created is a regular watchpoint,
-i.e. it will trigger when the memory location is accessed for writing.
-@xref{Set Watchpoints, , Setting watchpoints}.
+i.e., it will trigger when the memory location is accessed for writing.
+@xref{Set Watchpoints, , Setting Watchpoints}.
Note that @samp{-break-list} will report a single list of watchpoints and
breakpoints inserted.
(gdb)
-exec-continue
^running
-^done,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@},
+(gdb)
+*stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="x"@},
value=@{old="-268439212",new="55"@},
frame=@{func="main",args=[],file="recursive2.c",
fullname="/home/foo/bar/recursive2.c",line="5"@}
(gdb)
-exec-continue
^running
-^done,reason="watchpoint-trigger",
+(gdb)
+*stopped,reason="watchpoint-trigger",
wpt=@{number="5",exp="C"@},value=@{old="-276895068",new="3"@},
frame=@{func="callee4",args=[],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
(gdb)
-exec-continue
^running
-^done,reason="watchpoint-scope",wpnum="5",
+(gdb)
+*stopped,reason="watchpoint-scope",wpnum="5",
frame=@{func="callee3",args=[@{name="strarg",
value="0x11940 \"A string argument.\""@}],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
(gdb)
-exec-continue
^running
-^done,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@},
+(gdb)
+*stopped,reason="watchpoint-trigger",wpt=@{number="2",exp="C"@},
value=@{old="-276895068",new="3"@},
frame=@{func="callee4",args=[],
file="../../../devo/gdb/testsuite/gdb.mi/basics.c",
If blanks are needed as
part of a directory name, double-quotes should be used around
the name. In the command output, the path will show up separated
-by the system directory-separator character. The directory-seperator
+by the system directory-separator character. The directory-separator
character must not be used
in any directory name.
If no directories are specified, the current search path is displayed.
If blanks are needed as
part of a directory name, double-quotes should be used around
the name. In the command output, the path will show up separated
-by the system directory-separator character. The directory-seperator
+by the system directory-separator character. The directory-separator
character must not be used
in any directory name.
If no directories are specified, the current path is displayed.
Show the current working directory.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{pwd}.
-thread-info
@end smallexample
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
No equivalent.
@section @sc{gdb/mi} Program Execution
These are the asynchronous commands which generate the out-of-band
-record @samp{*stopped}. Currently GDB only really executes
+record @samp{*stopped}. Currently @value{GDBN} only really executes
asynchronously with remote targets and this interaction is mimicked in
other cases.
Display a list of the arguments for the frames between @var{low-frame}
and @var{high-frame} (inclusive). If @var{low-frame} and
-@var{high-frame} are not provided, list the arguments for the whole call
-stack.
+@var{high-frame} are not provided, list the arguments for the whole
+call stack. If the two arguments are equal, show the single frame
+at the corresponding level. It is an error if @var{low-frame} is
+larger than the actual number of frames. On the other hand,
+@var{high-frame} may be larger than the actual number of frames, in
+which case only existing frames will be returned.
The @var{show-values} argument must have a value of 0 or 1. A value of
0 means that only the names of the arguments are listed, a value of 1
@table @samp
@item @var{level}
-The frame number, 0 being the topmost frame, i.e. the innermost function.
+The frame number, 0 being the topmost frame, i.e., the innermost function.
@item @var{addr}
The @code{$pc} value for that frame.
@item @var{func}
If invoked without arguments, this command prints a backtrace for the
whole stack. If given two integer arguments, it shows the frames whose
levels are between the two arguments (inclusive). If the two arguments
-are equal, it shows the single frame at the corresponding level.
+are equal, it shows the single frame at the corresponding level. It is
+an error if @var{low-frame} is larger than the actual number of
+frames. On the other hand, @var{high-frame} may be larger than the
+actual number of frames, in which case only existing frames will be returned.
@subsubheading @value{GDBN} Command
type and value for simple data types and the name and type for arrays,
structures and unions. In this last case, a frontend can immediately
display the value of simple data types and create variable objects for
-other data types when the the user wishes to explore their values in
+other data types when the user wishes to explore their values in
more detail.
@subsubheading @value{GDBN} Command
@node GDB/MI Variable Objects
@section @sc{gdb/mi} Variable Objects
+@ignore
@subheading Motivation for Variable Objects in @sc{gdb/mi}
@item @code{-stack-select-frame}
@end itemize
-@subheading Introduction to Variable Objects in @sc{gdb/mi}
+@end ignore
+
+@subheading Introduction to Variable Objects
@cindex variable objects in @sc{gdb/mi}
-The basic idea behind variable objects is the creation of a named object
-to represent a variable, an expression, a memory location or even a CPU
-register. For each object created, a set of operations is available for
-examining or changing its properties.
-
-Furthermore, complex data types, such as C structures, are represented
-in a tree format. For instance, the @code{struct} type variable is the
-root and the children will represent the struct members. If a child
-is itself of a complex type, it will also have children of its own.
-Appropriate language differences are handled for C, C@t{++} and Java.
-
-When returning the actual values of the objects, this facility allows
-for the individual selection of the display format used in the result
-creation. It can be chosen among: binary, decimal, hexadecimal, octal
-and natural. Natural refers to a default format automatically
-chosen based on the variable type (like decimal for an @code{int}, hex
-for pointers, etc.).
+
+Variable objects are "object-oriented" MI interface for examining and
+changing values of expressions. Unlike some other MI interfaces that
+work with expressions, variable objects are specifically designed for
+simple and efficient presentation in the frontend. A variable object
+is identified by string name. When a variable object is created, the
+frontend specifies the expression for that variable object. The
+expression can be a simple variable, or it can be an arbitrary complex
+expression, and can even involve CPU registers. After creating a
+variable object, the frontend can invoke other variable object
+operations---for example to obtain or change the value of a variable
+object, or to change display format.
+
+Variable objects have hierarchical tree structure. Any variable object
+that corresponds to a composite type, such as structure in C, has
+a number of child variable objects, for example corresponding to each
+element of a structure. A child variable object can itself have
+children, recursively. Recursion ends when we reach
+leaf variable objects, which always have built-in types. Child variable
+objects are created only by explicit request, so if a frontend
+is not interested in the children of a particular variable object, no
+child will be created.
+
+For a leaf variable object it is possible to obtain its value as a
+string, or set the value from a string. String value can be also
+obtained for a non-leaf variable object, but it's generally a string
+that only indicates the type of the object, and does not list its
+contents. Assignment to a non-leaf variable object is not allowed.
+
+A frontend does not need to read the values of all variable objects each time
+the program stops. Instead, MI provides an update command that lists all
+variable objects whose values has changed since the last update
+operation. This considerably reduces the amount of data that must
+be transferred to the frontend. As noted above, children variable
+objects are created on demand, and only leaf variable objects have a
+real value. As result, gdb will read target memory only for leaf
+variables that frontend has created.
+
+The automatic update is not always desirable. For example, a frontend
+might want to keep a value of some expression for future reference,
+and never update it. For another example, fetching memory is
+relatively slow for embedded targets, so a frontend might want
+to disable automatic update for the variables that are either not
+visible on the screen, or ``closed''. This is possible using so
+called ``frozen variable objects''. Such variable objects are never
+implicitly updated.
The following is the complete set of @sc{gdb/mi} operations defined to
access this functionality:
@item @code{-var-create}
@tab create a variable object
@item @code{-var-delete}
-@tab delete the variable object and its children
+@tab delete the variable object and/or its children
@item @code{-var-set-format}
@tab set the display format of this variable
@item @code{-var-show-format}
@item @code{-var-info-type}
@tab show the type of this variable object
@item @code{-var-info-expression}
-@tab print what this variable object represents
+@tab print parent-relative expression that this variable object represents
+@item @code{-var-info-path-expression}
+@tab print full expression that this variable object represents
@item @code{-var-show-attributes}
@tab is this variable editable? does it exist here?
@item @code{-var-evaluate-expression}
@tab set the value of this variable
@item @code{-var-update}
@tab update the variable and its children
+@item @code{-var-set-frozen}
+@tab set frozeness attribute
@end multitable
In the next subsection we describe each operation in detail and suggest
@subsubheading Synopsis
@smallexample
- -var-delete @var{name}
+ -var-delete [ -c ] @var{name}
@end smallexample
Deletes a previously created variable object and all of its children.
+With the @samp{-c} option, just deletes the children.
Returns an error if the object @var{name} is not found.
@{binary | decimal | hexadecimal | octal | natural@}
@end smallexample
+The natural format is the default format choosen automatically
+based on the variable type (like decimal for an @code{int}, hex
+for pointers, etc.).
+
+For a variable with children, the format is set only on the
+variable itself, and the children are not affected.
@subheading The @code{-var-show-format} Command
@findex -var-show-format
-var-info-expression @var{name}
@end smallexample
-Returns what is represented by the variable object @var{name}:
+Returns a string that is suitable for presenting this
+variable object in user interface. The string is generally
+not valid expression in the current language, and cannot be evaluated.
+
+For example, if @code{a} is an array, and variable object
+@code{A} was created for @code{a}, then we'll get this output:
@smallexample
- lang=@var{lang-spec},exp=@var{expression}
+(gdb) -var-info-expression A.1
+^done,lang="C",exp="1"
@end smallexample
@noindent
-where @var{lang-spec} is @code{@{"C" | "C++" | "Java"@}}.
+Here, the values of @code{lang} can be @code{@{"C" | "C++" | "Java"@}}.
+
+Note that the output of the @code{-var-list-children} command also
+includes those expressions, so the @code{-var-info-expression} command
+is of limited use.
+
+@subheading The @code{-var-info-path-expression} Command
+@findex -var-info-path-expression
+
+@subsubheading Synopsis
+
+@smallexample
+ -var-info-path-expression @var{name}
+@end smallexample
+
+Returns an expression that can be evaluated in the current
+context and will yield the same value that a variable object has.
+Compare this with the @code{-var-info-expression} command, which
+result can be used only for UI presentation. Typical use of
+the @code{-var-info-path-expression} command is creating a
+watchpoint from a variable object.
+
+For example, suppose @code{C} is a C@t{++} class, derived from class
+@code{Base}, and that the @code{Base} class has a member called
+@code{m_size}. Assume a variable @code{c} is has the type of
+@code{C} and a variable object @code{C} was created for variable
+@code{c}. Then, we'll get this output:
+@smallexample
+(gdb) -var-info-path-expression C.Base.public.m_size
+^done,path_expr=((Base)c).m_size)
+@end smallexample
@subheading The @code{-var-show-attributes} Command
@findex -var-show-attributes
@end smallexample
Evaluates the expression that is represented by the specified variable
-object and returns its value as a string in the current format specified
-for the object:
+object and returns its value as a string. The format of the
+string can be changed using the @code{-var-set-format} command.
@smallexample
value=@var{value}
-var-update [@var{print-values}] @{@var{name} | "*"@}
@end smallexample
-Update the value of the variable object @var{name} by evaluating its
-expression after fetching all the new values from memory or registers.
-A @samp{*} causes all existing variable objects to be updated. The
-option @var{print-values} determines whether names both and values, or
-just names are printed in the manner described for
-@code{-var-list-children} (@pxref{-var-list-children}).
+Reevaluate the expressions corresponding to the variable object
+@var{name} and all its direct and indirect children, and return the
+list of variable objects whose values have changed; @var{name} must
+be a root variable object. Here, ``changed'' means that the result of
+@code{-var-evaluate-expression} before and after the
+@code{-var-update} is different. If @samp{*} is used as the variable
+object names, all existing variable objects are updated, except
+for frozen ones (@pxref{-var-set-frozen}). The option
+@var{print-values} determines whether both names and values, or just
+names are printed. The possible values of this options are the same
+as for @code{-var-list-children} (@pxref{-var-list-children}). It is
+recommended to use the @samp{--all-values} option, to reduce the
+number of MI commands needed on each program stop.
+
@subsubheading Example
(gdb)
@end smallexample
+@anchor{-var-update}
+The field in_scope may take three values:
+
+@table @code
+@item "true"
+The variable object's current value is valid.
+
+@item "false"
+The variable object does not currently hold a valid value but it may
+hold one in the future if its associated expression comes back into
+scope.
+
+@item "invalid"
+The variable object no longer holds a valid value.
+This can occur when the executable file being debugged has changed,
+either through recompilation or by using the @value{GDBN} @code{file}
+command. The front end should normally choose to delete these variable
+objects.
+@end table
+
+In the future new values may be added to this list so the front should
+be prepared for this possibility. @xref{GDB/MI Development and Front Ends, ,@sc{GDB/MI} Development and Front Ends}.
+
+@subheading The @code{-var-set-frozen} Command
+@findex -var-set-frozen
+@anchor{-var-set-frozen}
+
+@subsubheading Synopsis
+
+@smallexample
+ -var-set-frozen @var{name} @var{flag}
+@end smallexample
+
+Set the frozenness flag on the variable object @var{name}. The
+@var{flag} parameter should be either @samp{1} to make the variable
+frozen or @samp{0} to make it unfrozen. If a variable object is
+frozen, then neither itself, nor any of its children, are
+implicitly updated by @code{-var-update} of
+a parent variable or by @code{-var-update *}. Only
+@code{-var-update} of the variable itself will update its value and
+values of its children. After a variable object is unfrozen, it is
+implicitly updated by all subsequent @code{-var-update} operations.
+Unfreezing a variable does not update it, only subsequent
+@code{-var-update} does.
+
+@subsubheading Example
+
+@smallexample
+(gdb)
+-var-set-frozen V 1
+^done
+(gdb)
+@end smallexample
+
+
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Data Manipulation
@section @sc{gdb/mi} Data Manipulation
@c REMOVED FROM THE INTERFACE.
@c @subheading -data-assign
@c Change the value of a program variable. Plenty of side effects.
-@c @subsubheading GDB command
+@c @subsubheading GDB Command
@c set variable
@c @subsubheading Example
@c N.A.
@item @var{linenum}
is the line number to disassemble around
@item @var{lines}
-is the the number of disassembly lines to be produced. If it is -1,
+is the number of disassembly lines to be produced. If it is -1,
the whole function will be disassembled, in case no @var{end-addr} is
specified. If @var{end-addr} is specified as a non-zero value, and
@var{lines} is lower than the number of disassembly lines between
@end itemize
Note that whatever included in the instruction field, is not manipulated
-directely by @sc{gdb/mi}, i.e. it is not possible to adjust its format.
+directly by @sc{gdb/mi}, i.e., it is not possible to adjust its format.
@subsubheading @value{GDBN} Command
@item @var{word-format}
The format to be used to print the memory words. The notation is the
same as for @value{GDBN}'s @code{print} command (@pxref{Output Formats,
-,Output formats}).
+,Output Formats}).
@item @var{word-size}
The size of each memory word in bytes.
List the source files for the current executable.
-It will always output the filename, but only when GDB can find the absolute
-file name of a source file, will it output the fullname.
+It will always output the filename, but only when @value{GDBN} can find
+the absolute file name of a source file, will it output the fullname.
@subsubheading @value{GDBN} Command
@end smallexample
@ignore
-@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-@node GDB/MI Kod Commands
-@section @sc{gdb/mi} Kod Commands
-
-The Kod commands are not implemented.
-
-@c @subheading -kod-info
-
-@c @subheading -kod-list
-
-@c @subheading -kod-list-object-types
-
-@c @subheading -kod-show
-
@c %%%%%%%%%%%%%%%%%%%%%%%%%%%% SECTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@node GDB/MI Memory Overlay Commands
@section @sc{gdb/mi} Memory Overlay Commands
Attach to a process @var{pid} or a file @var{file} outside of @value{GDBN}.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{attach}.
Detach from the remote target which normally resumes its execution.
There's no output.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{detach}.
@subsubheading Synopsis
-@example
+@smallexample
-target-disconnect
-@end example
+@end smallexample
Disconnect from the remote target. There's no output and the target is
generally not resumed.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{disconnect}.
The type of target, for instance @samp{async}, @samp{remote}, etc.
@item @var{parameters}
Device names, host names and the like. @xref{Target Commands, ,
-Commands for managing targets}, for more details.
+Commands for Managing Targets}, for more details.
@end table
The output is a connection notification, followed by the address at
Show the current value of a @value{GDBN} variable.
-@subsubheading @value{GDBN} command
+@subsubheading @value{GDBN} Command
The corresponding @value{GDBN} command is @samp{show}.
(gdb)
@end smallexample
+@subheading The @code{-enable-timings} Command
+@findex -enable-timings
+
+@subheading Synopsis
+
+@smallexample
+-enable-timings [yes | no]
+@end smallexample
+
+Toggle the printing of the wallclock, user and system times for an MI
+command as a field in its output. This command is to help frontend
+developers optimize the performance of their code. No argument is
+equivalent to @samp{yes}.
+
+@subheading @value{GDBN} Command
+
+No equivalent.
+
+@subheading Example
+
+@smallexample
+(gdb)
+-enable-timings
+^done
+(gdb)
+-break-insert main
+^done,bkpt=@{number="1",type="breakpoint",disp="keep",enabled="y",
+addr="0x080484ed",func="main",file="myprog.c",
+fullname="/home/nickrob/myprog.c",line="73",times="0"@},
+time=@{wallclock="0.05185",user="0.00800",system="0.00000"@}
+(gdb)
+-enable-timings no
+^done
+(gdb)
+-exec-run
+^running
+(gdb)
+*stopped,reason="breakpoint-hit",bkptno="1",thread-id="0",
+frame=@{addr="0x080484ed",func="main",args=[@{name="argc",value="1"@},
+@{name="argv",value="0xbfb60364"@}],file="myprog.c",
+fullname="/home/nickrob/myprog.c",line="73"@}
+(gdb)
+@end smallexample
+
@node Annotations
@chapter @value{GDBN} Annotations
similar programs which want to interact with @value{GDBN} at a
relatively high level.
-The annotation mechanism has largely been superseeded by @sc{gdb/mi}
+The annotation mechanism has largely been superseded by @sc{gdb/mi}
(@pxref{GDB/MI}).
@ignore
@menu
* Annotations Overview:: What annotations are; the general syntax.
+* Server Prefix:: Issuing a command without affecting user state.
* Prompting:: Annotations marking @value{GDBN}'s need for input.
* Errors:: Annotations for error messages.
* Invalidation:: Some annotations describe things now invalid.
@option{--annotate} command line option (@pxref{Mode Options}), controls
how much information @value{GDBN} prints together with its prompt,
values of expressions, source lines, and other types of output. Level 0
-is for no anntations, level 1 is for use when @value{GDBN} is run as a
+is for no annotations, level 1 is for use when @value{GDBN} is run as a
subprocess of @sc{gnu} Emacs, level 3 is the maximum annotation suitable
for programs that control @value{GDBN}, and level 2 annotations have
been made obsolete (@pxref{Limitations, , Limitations of the Annotation
denotes a @samp{control-z} character) are annotations; the rest is
output from @value{GDBN}.
+@node Server Prefix
+@section The Server Prefix
+@cindex server prefix
+
+If you prefix a command with @samp{server } then it will not affect
+the command history, nor will it affect @value{GDBN}'s notion of which
+command to repeat if @key{RET} is pressed on a line by itself. This
+means that commands can be run behind a user's back by a front-end in
+a transparent manner.
+
+The server prefix does not affect the recording of values into the value
+history; to print a value without recording it into the value history,
+use the @code{output} command instead of the @code{print} command.
+
@node Prompting
@section Annotation for @value{GDBN} Input
The input types are
@table @code
-@findex pre-prompt
-@findex prompt
-@findex post-prompt
+@findex pre-prompt annotation
+@findex prompt annotation
+@findex post-prompt annotation
@item prompt
When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt).
-@findex pre-commands
-@findex commands
-@findex post-commands
+@findex pre-commands annotation
+@findex commands annotation
+@findex post-commands annotation
@item commands
When @value{GDBN} prompts for a set of commands, like in the @code{commands}
command. The annotations are repeated for each command which is input.
-@findex pre-overload-choice
-@findex overload-choice
-@findex post-overload-choice
+@findex pre-overload-choice annotation
+@findex overload-choice annotation
+@findex post-overload-choice annotation
@item overload-choice
When @value{GDBN} wants the user to select between various overloaded functions.
-@findex pre-query
-@findex query
-@findex post-query
+@findex pre-query annotation
+@findex query annotation
+@findex post-query annotation
@item query
When @value{GDBN} wants the user to confirm a potentially dangerous operation.
-@findex pre-prompt-for-continue
-@findex prompt-for-continue
-@findex post-prompt-for-continue
+@findex pre-prompt-for-continue annotation
+@findex prompt-for-continue annotation
+@findex post-prompt-for-continue annotation
@item prompt-for-continue
When @value{GDBN} is asking the user to press return to continue. Note: Don't
expect this to work well; instead use @code{set height 0} to disable
@section Errors
@cindex annotations for errors, warnings and interrupts
-@findex quit
+@findex quit annotation
@smallexample
^Z^Zquit
@end smallexample
This annotation occurs right before @value{GDBN} responds to an interrupt.
-@findex error
+@findex error annotation
@smallexample
^Z^Zerror
@end smallexample
does not necessarily mean that @value{GDBN} is immediately returning all the way
to the top level.
-@findex error-begin
+@findex error-begin annotation
A quit or error annotation may be preceded by
@smallexample
changed.
@table @code
-@findex frames-invalid
+@findex frames-invalid annotation
@item ^Z^Zframes-invalid
The frames (for example, output from the @code{backtrace} command) may
have changed.
-@findex breakpoints-invalid
+@findex breakpoints-invalid annotation
@item ^Z^Zbreakpoints-invalid
The breakpoints may have changed. For example, the user just added or
@section Running the Program
@cindex annotations for running programs
-@findex starting
-@findex stopping
+@findex starting annotation
+@findex stopping annotation
When the program starts executing due to a @value{GDBN} command such as
@code{step} or @code{continue},
annotations describe how the program stopped.
@table @code
-@findex exited
+@findex exited annotation
@item ^Z^Zexited @var{exit-status}
The program exited, and @var{exit-status} is the exit status (zero for
successful exit, otherwise nonzero).
-@findex signalled
-@findex signal-name
-@findex signal-name-end
-@findex signal-string
-@findex signal-string-end
+@findex signalled annotation
+@findex signal-name annotation
+@findex signal-name-end annotation
+@findex signal-string annotation
+@findex signal-string-end annotation
@item ^Z^Zsignalled
The program exited with a signal. After the @code{^Z^Zsignalled}, the
annotation continues:
@var{intro-text}, @var{middle-text}, and @var{end-text} are for the
user's benefit and have no particular format.
-@findex signal
+@findex signal annotation
@item ^Z^Zsignal
The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is
just saying that the program received the signal, not that it was
terminated with it.
-@findex breakpoint
+@findex breakpoint annotation
@item ^Z^Zbreakpoint @var{number}
The program hit breakpoint number @var{number}.
-@findex watchpoint
+@findex watchpoint annotation
@item ^Z^Zwatchpoint @var{number}
The program hit watchpoint number @var{number}.
@end table
@section Displaying Source
@cindex annotations for source display
-@findex source
+@findex source annotation
The following annotation is used instead of displaying source code:
@smallexample
@end menu
@node Bug Criteria
-@section Have you found a bug?
+@section Have You Found a Bug?
@cindex bug criteria
If you are not sure whether you have found a bug, here are some guidelines:
@end itemize
@node Bug Reporting
-@section How to report bugs
+@section How to Report Bugs
@cindex bug reports
@cindex @value{GDBN} bugs, reporting
@c should add a web page ref...
In any event, we also recommend that you submit bug reports for
-@value{GDBN}. The prefered method is to submit them directly using
+@value{GDBN}. The preferred method is to submit them directly using
@uref{http://www.gnu.org/software/gdb/bugs/, @value{GDBN}'s Bugs web
page}. Alternatively, the @email{bug-gdb@@gnu.org, e-mail gateway} can
be used.
@item
What compiler (and its version) was used to compile the program you are
debugging---e.g.@: ``@value{GCC}--2.8.1'', or ``HP92453-01 A.10.32.03 HP
-C Compiler''. For GCC, you can say @code{gcc --version} to get this
-information; for other compilers, see the documentation for those
-compilers.
+C Compiler''. For @value{NGCC}, you can say @kbd{@value{GCC} --version}
+to get this information; for other compilers, see the documentation for
+those compilers.
@item
The command arguments you gave the compiler to compile your example and
directory.
If you have @TeX{} and a @sc{dvi} printer program installed, you can
-typeset and print this manual. First switch to the the @file{gdb}
+typeset and print this manual. First switch to the @file{gdb}
subdirectory of the main source directory (for example, to
@file{gdb-@value{GDBVN}/gdb}) and type:
@node Installing GDB
@appendix Installing @value{GDBN}
-@cindex configuring @value{GDBN}
@cindex installation
-@cindex configuring @value{GDBN}, and source tree subdirectories
-@value{GDBN} comes with a @code{configure} script that automates the process
+@menu
+* Requirements:: Requirements for building @value{GDBN}
+* Running Configure:: Invoking the @value{GDBN} @file{configure} script
+* Separate Objdir:: Compiling @value{GDBN} in another directory
+* Config Names:: Specifying names for hosts and targets
+* Configure Options:: Summary of options for configure
+@end menu
+
+@node Requirements
+@section Requirements for Building @value{GDBN}
+@cindex building @value{GDBN}, requirements for
+
+Building @value{GDBN} requires various tools and packages to be available.
+Other packages will be used only if they are found.
+
+@heading Tools/Packages Necessary for Building @value{GDBN}
+@table @asis
+@item ISO C90 compiler
+@value{GDBN} is written in ISO C90. It should be buildable with any
+working C90 compiler, e.g.@: GCC.
+
+@end table
+
+@heading Tools/Packages Optional for Building @value{GDBN}
+@table @asis
+@item Expat
+@anchor{Expat}
+@value{GDBN} can use the Expat XML parsing library. This library may be
+included with your operating system distribution; if it is not, you
+can get the latest version from @url{http://expat.sourceforge.net}.
+The @file{configure} script will search for this library in several
+standard locations; if it is installed in an unusual path, you can
+use the @option{--with-libexpat-prefix} option to specify its location.
+
+Expat is used for remote protocol memory maps (@pxref{Memory Map Format})
+and for target descriptions (@pxref{Target Descriptions}).
+
+@end table
+
+@node Running Configure
+@section Invoking the @value{GDBN} @file{configure} Script
+@cindex configuring @value{GDBN}
+@value{GDBN} comes with a @file{configure} script that automates the process
of preparing @value{GDBN} for installation; you can then use @code{make} to
build the @code{gdb} program.
@iftex
source for the @sc{gnu} memory-mapped malloc package
@end table
-The simplest way to configure and build @value{GDBN} is to run @code{configure}
+The simplest way to configure and build @value{GDBN} is to run @file{configure}
from the @file{gdb-@var{version-number}} source directory, which in
this example is the @file{gdb-@value{GDBVN}} directory.
First switch to the @file{gdb-@var{version-number}} source directory
-if you are not already in it; then run @code{configure}. Pass the
+if you are not already in it; then run @file{configure}. Pass the
identifier for the platform on which @value{GDBN} will run as an
argument.
@noindent
where @var{host} is an identifier such as @samp{sun4} or
@samp{decstation}, that identifies the platform where @value{GDBN} will run.
-(You can often leave off @var{host}; @code{configure} tries to guess the
+(You can often leave off @var{host}; @file{configure} tries to guess the
correct value by examining your system.)
Running @samp{configure @var{host}} and then running @code{make} builds the
binaries, are left in the corresponding source directories.
@need 750
-@code{configure} is a Bourne-shell (@code{/bin/sh}) script; if your
+@file{configure} is a Bourne-shell (@code{/bin/sh}) script; if your
system does not recognize this automatically when you run a different
shell, you may need to run @code{sh} on it explicitly:
sh configure @var{host}
@end smallexample
-If you run @code{configure} from a directory that contains source
+If you run @file{configure} from a directory that contains source
directories for multiple libraries or programs, such as the
-@file{gdb-@value{GDBVN}} source directory for version @value{GDBVN}, @code{configure}
+@file{gdb-@value{GDBVN}} source directory for version @value{GDBVN},
+@file{configure}
creates configuration files for every directory level underneath (unless
you tell it not to, with the @samp{--norecursion} option).
-You should run the @code{configure} script from the top directory in the
+You should run the @file{configure} script from the top directory in the
source tree, the @file{gdb-@var{version-number}} directory. If you run
-@code{configure} from one of the subdirectories, you will configure only
+@file{configure} from one of the subdirectories, you will configure only
that subdirectory. That is usually not what you want. In particular,
-if you run the first @code{configure} from the @file{gdb} subdirectory
+if you run the first @file{configure} from the @file{gdb} subdirectory
of the @file{gdb-@var{version-number}} directory, you will omit the
configuration of @file{bfd}, @file{readline}, and other sibling
directories of the @file{gdb} subdirectory. This leads to build errors
that @value{GDBN} uses the shell to start your program---some systems refuse to
let @value{GDBN} debug child processes whose programs are not readable.
-@menu
-* Separate Objdir:: Compiling @value{GDBN} in another directory
-* Config Names:: Specifying names for hosts and targets
-* Configure Options:: Summary of options for configure
-@end menu
-
@node Separate Objdir
-@section Compiling @value{GDBN} in another directory
+@section Compiling @value{GDBN} in Another Directory
If you want to run @value{GDBN} versions for several host or target machines,
you need a different @code{gdb} compiled for each combination of
-host and target. @code{configure} is designed to make this easy by
+host and target. @file{configure} is designed to make this easy by
allowing you to generate each configuration in a separate subdirectory,
rather than in the source directory. If your @code{make} program
handles the @samp{VPATH} feature (@sc{gnu} @code{make} does), running
@code{make} in each of these directories builds the @code{gdb}
program specified there.
-To build @code{gdb} in a separate directory, run @code{configure}
+To build @code{gdb} in a separate directory, run @file{configure}
with the @samp{--srcdir} option to specify where to find the source.
-(You also need to specify a path to find @code{configure}
-itself from your working directory. If the path to @code{configure}
+(You also need to specify a path to find @file{configure}
+itself from your working directory. If the path to @file{configure}
would be the same as the argument to @samp{--srcdir}, you can leave out
the @samp{--srcdir} option; it is assumed.)
@end group
@end smallexample
-When @code{configure} builds a configuration using a remote source
+When @file{configure} builds a configuration using a remote source
directory, it creates a tree for the binaries with the same structure
(and using the same names) as the tree under the source directory. In
the example, you'd find the Sun 4 library @file{libiberty.a} in the
@value{GDBN} runs on one machine---the @dfn{host}---while debugging
programs that run on another machine---the @dfn{target}).
You specify a cross-debugging target by
-giving the @samp{--target=@var{target}} option to @code{configure}.
+giving the @samp{--target=@var{target}} option to @file{configure}.
When you run @code{make} to build a program or library, you must run
it in a configured directory---whatever directory you were in when you
-called @code{configure} (or one of its subdirectories).
+called @file{configure} (or one of its subdirectories).
-The @code{Makefile} that @code{configure} generates in each source
+The @code{Makefile} that @file{configure} generates in each source
directory also runs recursively. If you type @code{make} in a source
directory such as @file{gdb-@value{GDBVN}} (or in a separate configured
directory configured with @samp{--srcdir=@var{dirname}/gdb-@value{GDBVN}}), you
with each other.
@node Config Names
-@section Specifying names for hosts and targets
+@section Specifying Names for Hosts and Targets
-The specifications used for hosts and targets in the @code{configure}
+The specifications used for hosts and targets in the @file{configure}
script are based on a three-part naming scheme, but some short predefined
aliases are also supported. The full naming scheme encodes three pieces
of information in the following pattern:
or as the value for @var{target} in a @code{--target=@var{target}}
option. The equivalent full name is @samp{sparc-sun-sunos4}.
-The @code{configure} script accompanying @value{GDBN} does not provide
+The @file{configure} script accompanying @value{GDBN} does not provide
any query facility to list all supported host and target names or
-aliases. @code{configure} calls the Bourne shell script
+aliases. @file{configure} calls the Bourne shell script
@code{config.sub} to map abbreviations to full names; you can read the
script, if you wish, or you can use it to test your guesses on
abbreviations---for example:
directory (@file{gdb-@value{GDBVN}}, for version @value{GDBVN}).
@node Configure Options
-@section @code{configure} options
+@section @file{configure} Options
-Here is a summary of the @code{configure} options and arguments that
-are most often useful for building @value{GDBN}. @code{configure} also has
+Here is a summary of the @file{configure} options and arguments that
+are most often useful for building @value{GDBN}. @file{configure} also has
several other options not listed here. @inforef{What Configure
-Does,,configure.info}, for a full explanation of @code{configure}.
+Does,,configure.info}, for a full explanation of @file{configure}.
@smallexample
configure @r{[}--help@r{]}
@table @code
@item --help
-Display a quick summary of how to invoke @code{configure}.
+Display a quick summary of how to invoke @file{configure}.
@item --prefix=@var{dir}
Configure the source to install programs and files under directory
Use this option to make configurations in directories separate from the
@value{GDBN} source directories. Among other things, you can use this to
build (or maintain) several configurations simultaneously, in separate
-directories. @code{configure} writes configuration specific files in
+directories. @file{configure} writes configuration-specific files in
the current directory, but arranges for them to use the source in the
-directory @var{dirname}. @code{configure} creates directories under
+directory @var{dirname}. @file{configure} creates directories under
the working directory in parallel to the source directories below
@var{dirname}.
@item --norecursion
-Configure only the directory level where @code{configure} is executed; do not
+Configure only the directory level where @file{configure} is executed; do not
propagate configuration to subdirectories.
@item --target=@var{target}
@kindex maint demangle
@item maint demangle @var{name}
-Demangle a C@t{++} or Objective-C manled @var{name}.
+Demangle a C@t{++} or Objective-C mangled @var{name}.
@kindex maint deprecate
@kindex maint undeprecate
These commands take an optional parameter @var{message-text} that is
used as the text of the error or warning message.
-Here's an example of using @code{indernal-error}:
+Here's an example of using @code{internal-error}:
@smallexample
(@value{GDBP}) @kbd{maint internal-error testing, 1, 2}
This command prints, for each object file in the program, various data
about that object file followed by the byte cache (@dfn{bcache})
statistics for the object file. The objfile data includes the number
-of minimal, partical, full, and stabs symbols, the number of types
+of minimal, partial, full, and stabs symbols, the number of types
defined by the objfile, the number of as yet unexpanded psym tables,
the number of line tables and string tables, and the amount of memory
used by the various tables. The bcache statistics include the counts,
savings, and various measures of the hash table size and chain
lengths.
+@kindex maint print target-stack
+@cindex target stack description
+@item maint print target-stack
+A @dfn{target} is an interface between the debugger and a particular
+kind of file or process. Targets can be stacked in @dfn{strata},
+so that more than one target can potentially respond to a request.
+In particular, memory accesses will walk down the stack of targets
+until they find a target that is interested in handling that particular
+address.
+
+This command prints a short description of each layer that was pushed on
+the @dfn{target stack}, starting from the top layer down to the bottom one.
+
@kindex maint print type
@cindex type chain of a data type
@item maint print type @var{expr}
@item maint show-debug-regs
Control whether to show variables that mirror the x86 hardware debug
registers. Use @code{ON} to enable, @code{OFF} to disable. If
-enabled, the debug registers values are shown when GDB inserts or
+enabled, the debug registers values are shown when @value{GDBN} inserts or
removes a hardware breakpoint or watchpoint, and when the inferior
triggers a hardware-assisted breakpoint or watchpoint.
* Tracepoint Packets::
* Interrupts::
* Examples::
-* File-I/O remote protocol extension::
+* File-I/O Remote Protocol Extension::
+* Library List Format::
+* Memory Map Format::
@end menu
@node Overview
recognizes a packet meant for @value{GDBN}.
In the examples below, @samp{->} and @samp{<-} are used to indicate
-transmitted and received data respectfully.
+transmitted and received data, respectively.
@cindex protocol, @value{GDBN} remote serial
@cindex serial protocol, @value{GDBN} remote
exception of @samp{#} and @samp{$} (see @samp{X} packet for additional
exceptions).
-Fields within the packet should be separated using @samp{,} @samp{;} or
@cindex remote protocol, field separator
+Fields within the packet should be separated using @samp{,} @samp{;} or
@samp{:}. Except where otherwise noted all numbers are represented in
@sc{hex} with leading zeros suppressed.
@samp{:} could not appear as the third character in a packet (as it
would potentially conflict with the @var{sequence-id}).
+@cindex remote protocol, binary data
+@anchor{Binary Data}
+Binary data in most packets is encoded either as two hexadecimal
+digits per byte of binary data. This allowed the traditional remote
+protocol to work over connections which were only seven-bit clean.
+Some packets designed more recently assume an eight-bit clean
+connection, and use a more efficient encoding to send and receive
+binary data.
+
+The binary data representation uses @code{7d} (@sc{ascii} @samp{@}})
+as an escape character. Any escaped byte is transmitted as the escape
+character followed by the original character XORed with @code{0x20}.
+For example, the byte @code{0x7d} would be transmitted as the two
+bytes @code{0x7d 0x5d}. The bytes @code{0x23} (@sc{ascii} @samp{#}),
+@code{0x24} (@sc{ascii} @samp{$}), and @code{0x7d} (@sc{ascii}
+@samp{@}}) must always be escaped. Responses sent by the stub
+must also escape @code{0x2a} (@sc{ascii} @samp{*}), so that it
+is not interpreted as the start of a run-length encoded sequence
+(described next).
+
Response @var{data} can be run-length encoded to save space. A @samp{*}
means that the next character is an @sc{ascii} encoding giving a repeat count
which stands for that many repetitions of the character preceding the
The following table provides a complete list of all currently defined
@var{command}s and their corresponding response @var{data}.
-@xref{File-I/O remote protocol extension}, for details about the File
+@xref{File-I/O Remote Protocol Extension}, for details about the File
I/O extension of the remote protocol.
Each packet's description has a template showing the packet's overall
separate its components. For example, a template like @samp{foo
@var{bar} @var{baz}} describes a packet beginning with the three ASCII
bytes @samp{foo}, followed by a @var{bar}, followed directly by a
-@var{baz}. GDB does not transmit a space character between the
+@var{baz}. @value{GDBN} does not transmit a space character between the
@samp{foo} and the @var{bar}, or between the @var{bar} and the
@var{baz}.
@cindex @samp{F} packet
A reply from @value{GDBN} to an @samp{F} packet sent by the target.
This is part of the File-I/O protocol extension. @xref{File-I/O
-remote protocol extension}, for the specification.
+Remote Protocol Extension}, for the specification.
@item g
@anchor{read registers packet}
Each byte of register data is described by two hex digits. The bytes
with the register are transmitted in target byte order. The size of
each register and their position within the @samp{g} packet are
-determined by the @value{GDBN} internal macros
-@code{DEPRECATED_REGISTER_RAW_SIZE} and @code{REGISTER_NAME} macros. The
+determined by the @value{GDBN} internal gdbarch functions
+@code{DEPRECATED_REGISTER_RAW_SIZE} and @code{gdbarch_register_name}. The
specification of several standard @samp{g} packets is specified below.
@item E @var{NN}
for an error.
Reply:
@table @samp
@item @var{XX@dots{}}
-Memory contents; each byte is transmitted as a two-digit hexidecimal
+Memory contents; each byte is transmitted as a two-digit hexadecimal
number. The reply may contain fewer bytes than requested if the
server was able to read only part of the region of memory.
@item E @var{NN}
@cindex @samp{M} packet
Write @var{length} bytes of memory starting at address @var{addr}.
@var{XX@dots{}} is the data; each byte is transmitted as a two-digit
-hexidecimal number.
+hexadecimal number.
Reply:
@table @samp
@anchor{write register packet}
@cindex @samp{P} packet
Write register @var{n@dots{}} with value @var{r@dots{}}. The register
-number @var{n} is in hexidecimal, and @var{r@dots{}} contains two hex
+number @var{n} is in hexadecimal, and @var{r@dots{}} contains two hex
digits for each byte in the register (target byte order).
Reply:
@item vCont?
@cindex @samp{vCont?} packet
-Request a list of actions supporetd by the @samp{vCont} packet.
+Request a list of actions supported by the @samp{vCont} packet.
Reply:
@table @samp
The @samp{vCont} packet is not supported.
@end table
+@item vFlashErase:@var{addr},@var{length}
+@cindex @samp{vFlashErase} packet
+Direct the stub to erase @var{length} bytes of flash starting at
+@var{addr}. The region may enclose any number of flash blocks, but
+its start and end must fall on block boundaries, as indicated by the
+flash block size appearing in the memory map (@pxref{Memory Map
+Format}). @value{GDBN} groups flash memory programming operations
+together, and sends a @samp{vFlashDone} request after each group; the
+stub is allowed to delay erase operation until the @samp{vFlashDone}
+packet is received.
+
+Reply:
+@table @samp
+@item OK
+for success
+@item E @var{NN}
+for an error
+@end table
+
+@item vFlashWrite:@var{addr}:@var{XX@dots{}}
+@cindex @samp{vFlashWrite} packet
+Direct the stub to write data to flash address @var{addr}. The data
+is passed in binary form using the same encoding as for the @samp{X}
+packet (@pxref{Binary Data}). The memory ranges specified by
+@samp{vFlashWrite} packets preceding a @samp{vFlashDone} packet must
+not overlap, and must appear in order of increasing addresses
+(although @samp{vFlashErase} packets for higher addresses may already
+have been received; the ordering is guaranteed only between
+@samp{vFlashWrite} packets). If a packet writes to an address that was
+neither erased by a preceding @samp{vFlashErase} packet nor by some other
+target-specific method, the results are unpredictable.
+
+
+Reply:
+@table @samp
+@item OK
+for success
+@item E.memtype
+for vFlashWrite addressing non-flash memory
+@item E @var{NN}
+for an error
+@end table
+
+@item vFlashDone
+@cindex @samp{vFlashDone} packet
+Indicate to the stub that flash programming operation is finished.
+The stub is permitted to delay or batch the effects of a group of
+@samp{vFlashErase} and @samp{vFlashWrite} packets until a
+@samp{vFlashDone} packet is received. The contents of the affected
+regions of flash memory are unpredictable until the @samp{vFlashDone}
+request is completed.
+
@item X @var{addr},@var{length}:@var{XX@dots{}}
@anchor{X packet}
@cindex @samp{X} packet
Write data to memory, where the data is transmitted in binary.
@var{addr} is address, @var{length} is number of bytes,
-@samp{@var{XX}@dots{}} is binary data. The bytes @code{0x23}
-(@sc{ascii} @samp{#}), @code{0x24} (@sc{ascii} @samp{$}), and
-@code{0x7d} (@sc{ascii} @samp{@}}) are escaped using @code{0x7d}
-(@sc{ascii} @samp{@}}), and then XORed with @code{0x20}. For example,
-the byte @code{0x7d} would be transmitted as the two bytes @code{0x7d
-0x5d}.
+@samp{@var{XX}@dots{}} is binary data (@pxref{Binary Data}).
Reply:
@table @samp
receive any of the below as a reply. In the case of the @samp{C},
@samp{c}, @samp{S} and @samp{s} packets, that reply is only returned
when the target halts. In the below the exact meaning of @dfn{signal
-number} is poorly defined. In general one of the UNIX signal
-numbering conventions is used.
+number} is defined by the header @file{include/gdb/signals.h} in the
+@value{GDBN} source code.
As in the description of request packets, we include spaces in the
reply templates for clarity; these are not part of the reply packet's
@table @samp
@item S @var{AA}
-The program received signal number @var{AA} (a two-digit hexidecimal
-number).
+The program received signal number @var{AA} (a two-digit hexadecimal
+number). This is equivalent to a @samp{T} response with no
+@var{n}:@var{r} pairs.
@item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{}
@cindex @samp{T} packet reply
-The program received signal number @var{AA} (a two-digit hexidecimal
-number). Single-step and breakpoint traps are reported this way. The
-@samp{@var{n}:@var{r}} pairs give the values of important registers or
-other information:
-@enumerate
+The program received signal number @var{AA} (a two-digit hexadecimal
+number). This is equivalent to an @samp{S} response, except that the
+@samp{@var{n}:@var{r}} pairs can carry values of important registers
+and other information directly in the stop reply packet, reducing
+round-trip latency. Single-step and breakpoint traps are reported
+this way. Each @samp{@var{n}:@var{r}} pair is interpreted as follows:
+
+@itemize @bullet
@item
-If @var{n} is a hexidecimal number, it is a register number, and the
+If @var{n} is a hexadecimal number, it is a register number, and the
corresponding @var{r} gives that register's value. @var{r} is a
series of bytes in target byte order, with each byte given by a
two-digit hex number.
+
@item
If @var{n} is @samp{thread}, then @var{r} is the thread process ID, in
hex.
+
@item
-If @var{n} is @samp{watch}, @samp{rwatch}, or @samp{awatch}, then the
-packet indicates a watchpoint hit, and @var{r} is the data address, in
-hex.
+If @var{n} is a recognized @dfn{stop reason}, it describes a more
+specific event that stopped the target. The currently defined stop
+reasons are listed below. @var{aa} should be @samp{05}, the trap
+signal. At most one stop reason should be present.
+
@item
Otherwise, @value{GDBN} should ignore this @samp{@var{n}:@var{r}} pair
and go on to the next; this allows us to extend the protocol in the
future.
-@end enumerate
+@end itemize
-@item W @var{AA}
-The process exited, and @var{AA} is the exit status. This is only
+The currently defined stop reasons are:
+
+@table @samp
+@item watch
+@itemx rwatch
+@itemx awatch
+The packet indicates a watchpoint hit, and @var{r} is the data address, in
+hex.
+
+@cindex shared library events, remote reply
+@item library
+The packet indicates that the loaded libraries have changed.
+@value{GDBN} should use @samp{qXfer:libraries:read} to fetch a new
+list of loaded libraries. @var{r} is ignored.
+@end table
+
+@item W @var{AA}
+The process exited, and @var{AA} is the exit status. This is only
applicable to certain targets.
@item X @var{AA}
@var{call-id} is the identifier which says which host system call should
be called. This is just the name of the function. Translation into the
correct system call is only applicable as it's defined in @value{GDBN}.
-@xref{File-I/O remote protocol extension}, for a list of implemented
+@xref{File-I/O Remote Protocol Extension}, for a list of implemented
system calls.
@samp{@var{parameter}@dots{}} is a list of parameters as defined for
call a host system call on behalf of the target. @value{GDBN} replies
with an appropriate @samp{F} packet and keeps up waiting for the next
reply packet from the target. The latest @samp{C}, @samp{c}, @samp{S}
-or @samp{s} action is expected to be continued. @xref{File-I/O remote
-protocol extension}, for more details.
+or @samp{s} action is expected to be continued. @xref{File-I/O Remote
+Protocol Extension}, for more details.
@end table
Reply:
@table @samp
@item QC @var{pid}
-Where @var{pid} is an unsigned hexidecimal process id.
+Where @var{pid} is an unsigned hexadecimal process id.
@item @r{(anything else)}
Any other reply implies the old pid.
@end table
thread local variable. (This offset is obtained from the debug
information associated with the variable.)
-@var{lm} is the (big endian, hex encoded) OS/ABI specific encoding of the
+@var{lm} is the (big endian, hex encoded) OS/ABI-specific encoding of the
the load module associated with the thread local storage. For example,
a @sc{gnu}/Linux system will pass the link map address of the shared
object associated with the thread local storage under consideration.
An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub.
@end table
-Use of this request packet is controlled by the @code{set remote
-get-thread-local-storage-address} command (@pxref{Remote
-configuration, set remote get-thread-local-storage-address}).
-
@item qL @var{startflag} @var{threadcount} @var{nextthread}
Obtain thread information from RTOS. Where: @var{startflag} (one hex
digit) is one to indicate the first query and zero to indicate a
@item qOffsets
@cindex section offsets, remote request
@cindex @samp{qOffsets} packet
-Get section offsets that the target used when re-locating the downloaded
-image. @emph{Note: while a @code{Bss} offset is included in the
-response, @value{GDBN} ignores this and instead applies the @code{Data}
-offset to the @code{Bss} section.}
+Get section offsets that the target used when relocating the downloaded
+image.
Reply:
@table @samp
-@item Text=@var{xxx};Data=@var{yyy};Bss=@var{zzz}
+@item Text=@var{xxx};Data=@var{yyy}@r{[};Bss=@var{zzz}@r{]}
+Relocate the @code{Text} section by @var{xxx} from its original address.
+Relocate the @code{Data} section by @var{yyy} from its original address.
+If the object file format provides segment information (e.g.@: @sc{elf}
+@samp{PT_LOAD} program headers), @value{GDBN} will relocate entire
+segments by the supplied offsets.
+
+@emph{Note: while a @code{Bss} offset may be included in the response,
+@value{GDBN} ignores this and instead applies the @code{Data} offset
+to the @code{Bss} section.}
+
+@item TextSeg=@var{xxx}@r{[};DataSeg=@var{yyy}@r{]}
+Relocate the first segment of the object file, which conventionally
+contains program code, to a starting address of @var{xxx}. If
+@samp{DataSeg} is specified, relocate the second segment, which
+conventionally contains modifiable data, to a starting address of
+@var{yyy}. @value{GDBN} will report an error if the object file
+does not contain segment information, or does not contain at least
+as many segments as mentioned in the reply. Extra segments are
+kept at fixed offsets relative to the last relocated segment.
@end table
@item qP @var{mode} @var{threadid}
Reply: see @code{remote.c:remote_unpack_thread_info_response()}.
-@item qPart:@var{object}:read:@var{annex}:@var{offset},@var{length}
-@cindex read special object, remote request
-@cindex @samp{qPart} packet
-Read uninterpreted bytes from the target's special data area
-identified by the keyword @var{object}. Request @var{length} bytes
-starting at @var{offset} bytes into the data. The content and
-encoding of @var{annex} is specific to the object; it can supply
-additional details about what data to access.
-
-Since this packet is ambiguous with the older @code{qP} packet, we
-plan to rename it.
-
-Here are the specific requests of this form defined so far. All
-@samp{qPart:@var{object}:read:@dots{}} requests use the same reply
-formats, listed below.
-
-@table @samp
-@item qPart:auxv:read::@var{offset},@var{length}
-Access the target's @dfn{auxiliary vector}. @xref{OS Information,
-auxiliary vector}, and see @ref{Remote configuration,
-read-aux-vector-packet}. Note @var{annex} must be empty.
-@end table
+@item QPassSignals: @var{signal} @r{[};@var{signal}@r{]}@dots{}
+@cindex pass signals to inferior, remote request
+@cindex @samp{QPassSignals} packet
+@anchor{QPassSignals}
+Each listed @var{signal} should be passed directly to the inferior process.
+Signals are numbered identically to continue packets and stop replies
+(@pxref{Stop Reply Packets}). Each @var{signal} list item should be
+strictly greater than the previous item. These signals do not need to stop
+the inferior, or be reported to @value{GDBN}. All other signals should be
+reported to @value{GDBN}. Multiple @samp{QPassSignals} packets do not
+combine; any earlier @samp{QPassSignals} list is completely replaced by the
+new list. This packet improves performance when using @samp{handle
+@var{signal} nostop noprint pass}.
Reply:
@table @samp
@item OK
-The @var{offset} in the request is at the end of the data.
-There is no more data to be read.
-
-@item @var{XX}@dots{}
-Hex encoded data bytes read.
-This may be fewer bytes than the @var{length} in the request.
-
-@item E00
-The request was malformed, or @var{annex} was invalid.
+The request succeeded.
@item E @var{nn}
-The offset was invalid, or there was an error encountered reading the data.
-@var{nn} is a hex-encoded @code{errno} value.
-
-@item
-An empty reply indicates the @var{object} or @var{annex} string was not
-recognized by the stub.
-@end table
-
-@item qPart:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{}
-@cindex write data into object, remote request
-Write uninterpreted bytes into the target's special data area
-identified by the keyword @var{object}, starting at @var{offset} bytes
-into the data. @samp{@var{data}@dots{}} is the hex-encoded data to be
-written. The content and encoding of @var{annex} is specific to the
-object; it can supply additional details about what data to access.
-
-No requests of this form are presently in use. This specification
-serves as a placeholder to document the common format that new
-specific request specifications ought to use.
-
-Reply:
-@table @samp
-@item @var{nn}
-@var{nn} (hex encoded) is the number of bytes written.
-This may be fewer bytes than supplied in the request.
-
-@item E00
-The request was malformed, or @var{annex} was invalid.
-
-@item E @var{nn}
-The offset was invalid, or there was an error encountered writing the data.
-@var{nn} is a hex-encoded @code{errno} value.
+An error occurred. @var{nn} are hex digits.
@item
-An empty reply indicates the @var{object} or @var{annex} string was not
-recognized by the stub, or that the object does not support writing.
+An empty reply indicates that @samp{QPassSignals} is not supported by
+the stub.
@end table
-@item qPart:@var{object}:@var{operation}:@dots{}
-Requests of this form may be added in the future. When a stub does
-not recognize the @var{object} keyword, or its support for
-@var{object} does not recognize the @var{operation} keyword, the stub
-must respond with an empty packet.
+Use of this packet is controlled by the @code{set remote pass-signals}
+command (@pxref{Remote Configuration, set remote pass-signals}).
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
@item qRcmd,@var{command}
@cindex execute remote command, remote request
@cindex supported packets, remote query
@cindex features of the remote protocol
@cindex @samp{qSupported} packet
+@anchor{qSupported}
Tell the remote stub about features supported by @value{GDBN}, and
query the stub for features it supports. This packet allows
@value{GDBN} and the remote stub to take advantage of each others'
These are the currently defined stub features and their properties:
-@multitable @columnfractions 0.25 0.2 0.2 0.2
+@multitable @columnfractions 0.35 0.2 0.12 0.2
@c NOTE: The first row should be @headitem, but we do not yet require
@c a new enough version of Texinfo (4.7) to use @headitem.
-@item Packet Name
+@item Feature Name
@tab Value Required
@tab Default
@tab Probe Allowed
@tab @samp{-}
@tab No
+@item @samp{qXfer:auxv:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+@item @samp{qXfer:features:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+@item @samp{qXfer:libraries:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+@item @samp{qXfer:memory-map:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+@item @samp{qXfer:spu:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+@item @samp{qXfer:spu:write}
+@tab No
+@tab @samp{-}
+@tab Yes
+
+@item @samp{QPassSignals}
+@tab No
+@tab @samp{-}
+@tab Yes
+
@end multitable
These are the currently defined stub features, in more detail:
byte in its buffer for the NUL. If this stub feature is not supported,
@value{GDBN} guesses based on the size of the @samp{g} packet response.
+@item qXfer:auxv:read
+The remote stub understands the @samp{qXfer:auxv:read} packet
+(@pxref{qXfer auxiliary vector read}).
+
+@item qXfer:features:read
+The remote stub understands the @samp{qXfer:features:read} packet
+(@pxref{qXfer target description read}).
+
+@item qXfer:libraries:read
+The remote stub understands the @samp{qXfer:libraries:read} packet
+(@pxref{qXfer library list read}).
+
+@item qXfer:memory-map:read
+The remote stub understands the @samp{qXfer:memory-map:read} packet
+(@pxref{qXfer memory map read}).
+
+@item qXfer:spu:read
+The remote stub understands the @samp{qXfer:spu:read} packet
+(@pxref{qXfer spu read}).
+
+@item qXfer:spu:write
+The remote stub understands the @samp{qXfer:spu:write} packet
+(@pxref{qXfer spu write}).
+
+@item QPassSignals
+The remote stub understands the @samp{QPassSignals} packet
+(@pxref{QPassSignals}).
+
@end table
@item qSymbol::
@itemx qTStatus
@xref{Tracepoint Packets}.
+@item qXfer:@var{object}:read:@var{annex}:@var{offset},@var{length}
+@cindex read special object, remote request
+@cindex @samp{qXfer} packet
+@anchor{qXfer read}
+Read uninterpreted bytes from the target's special data area
+identified by the keyword @var{object}. Request @var{length} bytes
+starting at @var{offset} bytes into the data. The content and
+encoding of @var{annex} is specific to @var{object}; it can supply
+additional details about what data to access.
+
+Here are the specific requests of this form defined so far. All
+@samp{qXfer:@var{object}:read:@dots{}} requests use the same reply
+formats, listed below.
+
+@table @samp
+@item qXfer:auxv:read::@var{offset},@var{length}
+@anchor{qXfer auxiliary vector read}
+Access the target's @dfn{auxiliary vector}. @xref{OS Information,
+auxiliary vector}. Note @var{annex} must be empty.
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+
+@item qXfer:features:read:@var{annex}:@var{offset},@var{length}
+@anchor{qXfer target description read}
+Access the @dfn{target description}. @xref{Target Descriptions}. The
+annex specifies which XML document to access. The main description is
+always loaded from the @samp{target.xml} annex.
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+
+@item qXfer:libraries:read:@var{annex}:@var{offset},@var{length}
+@anchor{qXfer library list read}
+Access the target's list of loaded libraries. @xref{Library List Format}.
+The annex part of the generic @samp{qXfer} packet must be empty
+(@pxref{qXfer read}).
+
+Targets which maintain a list of libraries in the program's memory do
+not need to implement this packet; it is designed for platforms where
+the operating system manages the list of loaded libraries.
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+
+@item qXfer:memory-map:read::@var{offset},@var{length}
+@anchor{qXfer memory map read}
+Access the target's @dfn{memory-map}. @xref{Memory Map Format}. The
+annex part of the generic @samp{qXfer} packet must be empty
+(@pxref{qXfer read}).
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+
+@item qXfer:spu:read:@var{annex}:@var{offset},@var{length}
+@anchor{qXfer spu read}
+Read contents of an @code{spufs} file on the target system. The
+annex specifies which file to read; it must be of the form
+@file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID
+in the target process, and @var{name} identifes the @code{spufs} file
+in that context to be accessed.
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+@end table
+
+Reply:
+@table @samp
+@item m @var{data}
+Data @var{data} (@pxref{Binary Data}) has been read from the
+target. There may be more data at a higher address (although
+it is permitted to return @samp{m} even for the last valid
+block of data, as long as at least one byte of data was read).
+@var{data} may have fewer bytes than the @var{length} in the
+request.
+
+@item l @var{data}
+Data @var{data} (@pxref{Binary Data}) has been read from the target.
+There is no more data to be read. @var{data} may have fewer bytes
+than the @var{length} in the request.
+
+@item l
+The @var{offset} in the request is at the end of the data.
+There is no more data to be read.
+
+@item E00
+The request was malformed, or @var{annex} was invalid.
+
+@item E @var{nn}
+The offset was invalid, or there was an error encountered reading the data.
+@var{nn} is a hex-encoded @code{errno} value.
+
+@item
+An empty reply indicates the @var{object} string was not recognized by
+the stub, or that the object does not support reading.
+@end table
+
+@item qXfer:@var{object}:write:@var{annex}:@var{offset}:@var{data}@dots{}
+@cindex write data into object, remote request
+Write uninterpreted bytes into the target's special data area
+identified by the keyword @var{object}, starting at @var{offset} bytes
+into the data. @var{data}@dots{} is the binary-encoded data
+(@pxref{Binary Data}) to be written. The content and encoding of @var{annex}
+is specific to @var{object}; it can supply additional details about what data
+to access.
+
+Here are the specific requests of this form defined so far. All
+@samp{qXfer:@var{object}:write:@dots{}} requests use the same reply
+formats, listed below.
+
+@table @samp
+@item qXfer:@var{spu}:write:@var{annex}:@var{offset}:@var{data}@dots{}
+@anchor{qXfer spu write}
+Write @var{data} to an @code{spufs} file on the target system. The
+annex specifies which file to write; it must be of the form
+@file{@var{id}/@var{name}}, where @var{id} specifies an SPU context ID
+in the target process, and @var{name} identifes the @code{spufs} file
+in that context to be accessed.
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+@end table
+
+Reply:
+@table @samp
+@item @var{nn}
+@var{nn} (hex encoded) is the number of bytes written.
+This may be fewer bytes than supplied in the request.
+
+@item E00
+The request was malformed, or @var{annex} was invalid.
+
+@item E @var{nn}
+The offset was invalid, or there was an error encountered writing the data.
+@var{nn} is a hex-encoded @code{errno} value.
+
+@item
+An empty reply indicates the @var{object} string was not
+recognized by the stub, or that the object does not support writing.
+@end table
+
+@item qXfer:@var{object}:@var{operation}:@dots{}
+Requests of this form may be added in the future. When a stub does
+not recognize the @var{object} keyword, or its support for
+@var{object} does not recognize the @var{operation} keyword, the stub
+must respond with an empty packet.
+
@end table
@node Register Packet Format
The following @code{g}/@code{G} packets have previously been defined.
In the below, some thirty-two bit registers are transferred as
sixty-four bits. Those registers should be zero/sign extended (which?)
-to fill the space allocated. Register bytes are transfered in target
-byte order. The two nibbles within a register byte are transfered
+to fill the space allocated. Register bytes are transferred in target
+byte order. The two nibbles within a register byte are transferred
most-significant - least-significant.
@table @r
@item MIPS32
-All registers are transfered as thirty-two bit quantities in the order:
+All registers are transferred as thirty-two bit quantities in the order:
32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point
registers; fsr; fir; fp.
@item MIPS64
-All registers are transfered as sixty-four bit quantities (including
+All registers are transferred as sixty-four bit quantities (including
thirty-two bit registers such as @code{sr}). The ordering is the same
as @code{MIPS32}.
@item R @var{mask}
Collect the registers whose bits are set in @var{mask}. @var{mask} is
-a hexidecimal number whose @var{i}'th bit is set if register number
+a hexadecimal number whose @var{i}'th bit is set if register number
@var{i} should be collected. (The least significant bit is numbered
zero.) Note that @var{mask} may be any number of digits long; it may
not fit in a 32-bit word.
number @var{basereg}, plus @var{offset}. If @var{basereg} is
@samp{-1}, then the range has a fixed address: @var{offset} is the
address of the lowest byte to collect. The @var{basereg},
-@var{offset}, and @var{len} parameters are all unsigned hexidecimal
+@var{offset}, and @var{len} parameters are all unsigned hexadecimal
values (the @samp{-1} value for @var{basereg} is a special case).
@item X @var{len},@var{expr}
@table @samp
@item F @var{f}
The selected frame is number @var{n} in the trace frame buffer;
-@var{f} is a hexidecimal number. If @var{f} is @samp{-1}, then there
+@var{f} is a hexadecimal number. If @var{f} is @samp{-1}, then there
was no frame matching the criteria in the request packet.
@item T @var{t}
The selected trace frame records a hit of tracepoint number @var{t};
-@var{t} is a hexidecimal number.
+@var{t} is a hexadecimal number.
@end table
@item QTFrame:pc:@var{addr}
Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
currently selected frame whose PC is @var{addr};
-@var{addr} is a hexidecimal number.
+@var{addr} is a hexadecimal number.
@item QTFrame:tdp:@var{t}
Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
currently selected frame that is a hit of tracepoint @var{t}; @var{t}
-is a hexidecimal number.
+is a hexadecimal number.
@item QTFrame:range:@var{start}:@var{end}
Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
currently selected frame whose PC is between @var{start} (inclusive)
-and @var{end} (exclusive); @var{start} and @var{end} are hexidecimal
+and @var{end} (exclusive); @var{start} and @var{end} are hexadecimal
numbers.
@item QTFrame:outside:@var{start}:@var{end}
the Overview section (@pxref{Overview}). When a @code{0x03} byte is
transmitted as part of a packet, it is considered to be packet data
and does @emph{not} represent an interrupt. E.g., an @samp{X} packet
-(@pxref{X packet}, used for binary downloads, may include an unescaped
+(@pxref{X packet}), used for binary downloads, may include an unescaped
@code{0x03} as part of its packet.
Stubs are not required to recognize these interrupt mechanisms and the
-> @code{+}
@end smallexample
-@node File-I/O remote protocol extension
-@section File-I/O remote protocol extension
+@node File-I/O Remote Protocol Extension
+@section File-I/O Remote Protocol Extension
@cindex File-I/O remote protocol extension
@menu
* File-I/O Overview::
-* Protocol basics::
-* The F request packet::
-* The F reply packet::
-* The Ctrl-C message::
+* Protocol Basics::
+* The F Request Packet::
+* The F Reply Packet::
+* The Ctrl-C Message::
* Console I/O::
-* List of supported calls::
-* Protocol specific representation of datatypes::
+* List of Supported Calls::
+* Protocol-specific Representation of Datatypes::
* Constants::
* File-I/O Examples::
@end menu
the target is stopped to allow deterministic access to the target's
memory. Therefore File-I/O is not interruptible by target signals. On
the other hand, it is possible to interrupt File-I/O by a user interrupt
-(Ctrl-C) within @value{GDBN}.
+(@samp{Ctrl-C}) within @value{GDBN}.
The target's request to perform a host system call does not finish
the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means,
(@value{GDBP}) continue
<- target requests 'system call X'
target is stopped, @value{GDBN} executes system call
- -> GDB returns result
- ... target continues, GDB returns to wait for the target
+ -> @value{GDBN} returns result
+ ... target continues, @value{GDBN} returns to wait for the target
<- target hits breakpoint and sends a Txx packet
@end smallexample
named pipes, sockets or any other communication method on the host
system are not supported by this protocol.
-@node Protocol basics
-@subsection Protocol basics
+@node Protocol Basics
+@subsection Protocol Basics
@cindex protocol basics, file-i/o
The File-I/O protocol uses the @code{F} packet as the request as well
All parameters to the system call. Pointers are given as addresses
in the target memory address space. Pointers to strings are given as
pointer/length pair. Numerical values are given as they are.
-Numerical control flags are given in a protocol specific representation.
+Numerical control flags are given in a protocol-specific representation.
@end itemize
After having done the needed type and value coercion, the target continues
the latest continue or step action.
-@node The F request packet
-@subsection The @code{F} request packet
+@node The F Request Packet
+@subsection The @code{F} Request Packet
@cindex file-i/o request packet
@cindex @code{F} request packet
-@node The F reply packet
-@subsection The @code{F} reply packet
+@node The F Reply Packet
+@subsection The @code{F} Reply Packet
@cindex file-i/o reply packet
@cindex @code{F} reply packet
@table @samp
-@item F@var{retcode},@var{errno},@var{Ctrl-C flag};@var{call specific attachment}
+@item F@var{retcode},@var{errno},@var{Ctrl-C flag};@var{call-specific attachment}
@var{retcode} is the return code of the system call as hexadecimal value.
-@var{errno} is the @code{errno} set by the call, in protocol specific representation.
+@var{errno} is the @code{errno} set by the call, in protocol-specific
+representation.
This parameter can be omitted if the call was successful.
@var{Ctrl-C flag} is only sent if the user requested a break. In this
@end smallexample
@noindent
-assuming 4 is the protocol specific representation of @code{EINTR}.
+assuming 4 is the protocol-specific representation of @code{EINTR}.
@end table
-@node The Ctrl-C message
-@subsection The Ctrl-C message
+@node The Ctrl-C Message
+@subsection The @samp{Ctrl-C} Message
@cindex ctrl-c message, in file-i/o protocol
-If the Ctrl-C flag is set in the @value{GDBN}
-reply packet (@pxref{The F reply packet}),
+If the @samp{Ctrl-C} flag is set in the @value{GDBN}
+reply packet (@pxref{The F Reply Packet}),
the target should behave as if it had
gotten a break message. The meaning for the target is ``system call
interrupted by @code{SIGINT}''. Consequentially, the target should actually stop
(as with a break message) and return to @value{GDBN} with a @code{T02}
-packet.
+packet.
It's important for the target to know in which
state the system call was interrupted. There are two possible cases:
@subsection Console I/O
@cindex console i/o as part of file-i/o
-By default and if not explicitely closed by the target system, the file
+By default and if not explicitly closed by the target system, the file
descriptors 0, 1 and 2 are connected to the @value{GDBN} console. Output
on the @value{GDBN} console is handled as any other file output operation
(@code{write(1, @dots{})} or @code{write(2, @dots{})}). Console input is handled
@itemize @bullet
@item
-The user presses @kbd{Ctrl-C}. The behaviour is as explained above, and the
+The user types @kbd{Ctrl-c}. The behaviour is as explained above, and the
@code{read}
system call is treated as finished.
@item
-The user presses @kbd{Enter}. This is treated as end of input with a trailing
+The user presses @key{RET}. This is treated as end of input with a trailing
newline.
@item
-The user presses @kbd{Ctrl-D}. This is treated as end of input. No trailing
-character (neither newline nor Ctrl-D) is appended to the input.
+The user types @kbd{Ctrl-d}. This is treated as end of input. No trailing
+character (neither newline nor @samp{Ctrl-D}) is appended to the input.
@end itemize
is stopped at the user's request.
-@node List of supported calls
-@subsection List of supported calls
+@node List of Supported Calls
+@subsection List of Supported Calls
@cindex list of supported file-i/o calls
@menu
@item EFBIG
An attempt was made to write a file that exceeds the
-host specific maximum file size allowed.
+host-specific maximum file size allowed.
@item ENOSPC
No space on device to write the data.
protocol.
@end table
-@node Protocol specific representation of datatypes
-@subsection Protocol specific representation of datatypes
-@cindex protocol specific representation of datatypes, in file-i/o protocol
+@node Protocol-specific Representation of Datatypes
+@subsection Protocol-specific Representation of Datatypes
+@cindex protocol-specific representation of datatypes, in file-i/o protocol
@menu
-* Integral datatypes::
-* Pointer values::
-* Memory transfer::
+* Integral Datatypes::
+* Pointer Values::
+* Memory Transfer::
* struct stat::
* struct timeval::
@end menu
-@node Integral datatypes
-@unnumberedsubsubsec Integral datatypes
+@node Integral Datatypes
+@unnumberedsubsubsec Integral Datatypes
@cindex integral datatypes, in file-i/o protocol
The integral datatypes used in the system calls are @code{int},
structured datatype e.g.@: a @code{struct stat} have to be given in big endian
byte order.
-@node Pointer values
-@unnumberedsubsubsec Pointer values
+@node Pointer Values
+@unnumberedsubsubsec Pointer Values
@cindex pointer values, in file-i/o protocol
Pointers to target data are transmitted as they are. An exception
@code{123456/d}
@end smallexample
-@node Memory transfer
-@unnumberedsubsubsec Memory transfer
+@node Memory Transfer
+@unnumberedsubsubsec Memory Transfer
@cindex memory transfer, in file-i/o protocol
Structured data which is transferred using a memory read or write (for
-example, a @code{struct stat}) is expected to be in a protocol specific format
+example, a @code{struct stat}) is expected to be in a protocol-specific format
with all scalar multibyte datatypes being big endian. Translation to
this representation needs to be done both by the target before the @code{F}
packet is sent, and by @value{GDBN} before
@end smallexample
The integral datatypes conform to the definitions given in the
-appropriate section (see @ref{Integral datatypes}, for details) so this
+appropriate section (see @ref{Integral Datatypes}, for details) so this
structure is of size 64 bytes.
The values of several fields have a restricted meaning and/or
@end smallexample
The integral datatypes conform to the definitions given in the
-appropriate section (see @ref{Integral datatypes}, for details) so this
+appropriate section (see @ref{Integral Datatypes}, for details) so this
structure is of size 8 bytes.
@node Constants
values before and after the call as needed.
@menu
-* Open flags::
-* mode_t values::
-* Errno values::
-* Lseek flags::
+* Open Flags::
+* mode_t Values::
+* Errno Values::
+* Lseek Flags::
* Limits::
@end menu
-@node Open flags
-@unnumberedsubsubsec Open flags
+@node Open Flags
+@unnumberedsubsubsec Open Flags
@cindex open flags, in file-i/o protocol
All values are given in hexadecimal representation.
O_EXCL 0x800
@end smallexample
-@node mode_t values
-@unnumberedsubsubsec mode_t values
+@node mode_t Values
+@unnumberedsubsubsec mode_t Values
@cindex mode_t values, in file-i/o protocol
All values are given in octal representation.
S_IXOTH 01
@end smallexample
-@node Errno values
-@unnumberedsubsubsec Errno values
+@node Errno Values
+@unnumberedsubsubsec Errno Values
@cindex errno values, in file-i/o protocol
All values are given in decimal representation.
@code{EUNKNOWN} is used as a fallback error value if a host system returns
any error value not in the list of supported error numbers.
-@node Lseek flags
-@unnumberedsubsubsec Lseek flags
+@node Lseek Flags
+@unnumberedsubsubsec Lseek Flags
@cindex lseek flags, in file-i/o protocol
@smallexample
-> @code{F-1,9}
@end smallexample
-Example sequence of a read call, user presses Ctrl-C before syscall on
+Example sequence of a read call, user presses @kbd{Ctrl-c} before syscall on
host is called:
@smallexample
<- @code{T02}
@end smallexample
-Example sequence of a read call, user presses Ctrl-C after syscall on
+Example sequence of a read call, user presses @kbd{Ctrl-c} after syscall on
host is called:
@smallexample
<- @code{T02}
@end smallexample
+@node Library List Format
+@section Library List Format
+@cindex library list format, remote protocol
+
+On some platforms, a dynamic loader (e.g.@: @file{ld.so}) runs in the
+same process as your application to manage libraries. In this case,
+@value{GDBN} can use the loader's symbol table and normal memory
+operations to maintain a list of shared libraries. On other
+platforms, the operating system manages loaded libraries.
+@value{GDBN} can not retrieve the list of currently loaded libraries
+through memory operations, so it uses the @samp{qXfer:libraries:read}
+packet (@pxref{qXfer library list read}) instead. The remote stub
+queries the target's operating system and reports which libraries
+are loaded.
+
+The @samp{qXfer:libraries:read} packet returns an XML document which
+lists loaded libraries and their offsets. Each library has an
+associated name and one or more segment base addresses, which report
+where the library was loaded in memory. The segment bases are start
+addresses, not relocation offsets; they do not depend on the library's
+link-time base addresses.
+
+A simple memory map, with one loaded library relocated by a single
+offset, looks like this:
+
+@smallexample
+<library-list>
+ <library name="/lib/libc.so.6">
+ <segment address="0x10000000"/>
+ </library>
+</library-list>
+@end smallexample
+
+The format of a library list is described by this DTD:
+
+@smallexample
+<!-- library-list: Root element with versioning -->
+<!ELEMENT library-list (library)*>
+<!ATTLIST library-list version CDATA #FIXED "1.0">
+<!ELEMENT library (segment)*>
+<!ATTLIST library name CDATA #REQUIRED>
+<!ELEMENT segment EMPTY>
+<!ATTLIST segment address CDATA #REQUIRED>
+@end smallexample
+
+@node Memory Map Format
+@section Memory Map Format
+@cindex memory map format
+
+To be able to write into flash memory, @value{GDBN} needs to obtain a
+memory map from the target. This section describes the format of the
+memory map.
+
+The memory map is obtained using the @samp{qXfer:memory-map:read}
+(@pxref{qXfer memory map read}) packet and is an XML document that
+lists memory regions. The top-level structure of the document is shown below:
+
+@smallexample
+<?xml version="1.0"?>
+<!DOCTYPE memory-map
+ PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
+ "http://sourceware.org/gdb/gdb-memory-map.dtd">
+<memory-map>
+ region...
+</memory-map>
+@end smallexample
+
+Each region can be either:
+
+@itemize
+
+@item
+A region of RAM starting at @var{addr} and extending for @var{length}
+bytes from there:
+
+@smallexample
+<memory type="ram" start="@var{addr}" length="@var{length}"/>
+@end smallexample
+
+
+@item
+A region of read-only memory:
+
+@smallexample
+<memory type="rom" start="@var{addr}" length="@var{length}"/>
+@end smallexample
+
+
+@item
+A region of flash memory, with erasure blocks @var{blocksize}
+bytes in length:
+
+@smallexample
+<memory type="flash" start="@var{addr}" length="@var{length}">
+ <property name="blocksize">@var{blocksize}</property>
+</memory>
+@end smallexample
+
+@end itemize
+
+Regions must not overlap. @value{GDBN} assumes that areas of memory not covered
+by the memory map are RAM, and uses the ordinary @samp{M} and @samp{X}
+packets to write to addresses in such ranges.
+
+The formal DTD for memory map format is given below:
+
+@smallexample
+<!-- ................................................... -->
+<!-- Memory Map XML DTD ................................ -->
+<!-- File: memory-map.dtd .............................. -->
+<!-- .................................... .............. -->
+<!-- memory-map.dtd -->
+<!-- memory-map: Root element with versioning -->
+<!ELEMENT memory-map (memory | property)>
+<!ATTLIST memory-map version CDATA #FIXED "1.0.0">
+<!ELEMENT memory (property)>
+<!-- memory: Specifies a memory region,
+ and its type, or device. -->
+<!ATTLIST memory type CDATA #REQUIRED
+ start CDATA #REQUIRED
+ length CDATA #REQUIRED
+ device CDATA #IMPLIED>
+<!-- property: Generic attribute tag -->
+<!ELEMENT property (#PCDATA | property)*>
+<!ATTLIST property name CDATA #REQUIRED>
+@end smallexample
+
@include agentexpr.texi
+@node Target Descriptions
+@appendix Target Descriptions
+@cindex target descriptions
+
+@strong{Warning:} target descriptions are still under active development,
+and the contents and format may change between @value{GDBN} releases.
+The format is expected to stabilize in the future.
+
+One of the challenges of using @value{GDBN} to debug embedded systems
+is that there are so many minor variants of each processor
+architecture in use. It is common practice for vendors to start with
+a standard processor core --- ARM, PowerPC, or MIPS, for example ---
+and then make changes to adapt it to a particular market niche. Some
+architectures have hundreds of variants, available from dozens of
+vendors. This leads to a number of problems:
+
+@itemize @bullet
+@item
+With so many different customized processors, it is difficult for
+the @value{GDBN} maintainers to keep up with the changes.
+@item
+Since individual variants may have short lifetimes or limited
+audiences, it may not be worthwhile to carry information about every
+variant in the @value{GDBN} source tree.
+@item
+When @value{GDBN} does support the architecture of the embedded system
+at hand, the task of finding the correct architecture name to give the
+@command{set architecture} command can be error-prone.
+@end itemize
+
+To address these problems, the @value{GDBN} remote protocol allows a
+target system to not only identify itself to @value{GDBN}, but to
+actually describe its own features. This lets @value{GDBN} support
+processor variants it has never seen before --- to the extent that the
+descriptions are accurate, and that @value{GDBN} understands them.
+
+@value{GDBN} must be compiled with Expat support to support XML target
+descriptions. @xref{Expat}.
+
+@menu
+* Retrieving Descriptions:: How descriptions are fetched from a target.
+* Target Description Format:: The contents of a target description.
+* Predefined Target Types:: Standard types available for target
+ descriptions.
+* Standard Target Features:: Features @value{GDBN} knows about.
+@end menu
+
+@node Retrieving Descriptions
+@section Retrieving Descriptions
+
+Target descriptions can be read from the target automatically, or
+specified by the user manually. The default behavior is to read the
+description from the target. @value{GDBN} retrieves it via the remote
+protocol using @samp{qXfer} requests (@pxref{General Query Packets,
+qXfer}). The @var{annex} in the @samp{qXfer} packet will be
+@samp{target.xml}. The contents of the @samp{target.xml} annex are an
+XML document, of the form described in @ref{Target Description
+Format}.
+
+Alternatively, you can specify a file to read for the target description.
+If a file is set, the target will not be queried. The commands to
+specify a file are:
+
+@table @code
+@cindex set tdesc filename
+@item set tdesc filename @var{path}
+Read the target description from @var{path}.
+
+@cindex unset tdesc filename
+@item unset tdesc filename
+Do not read the XML target description from a file. @value{GDBN}
+will use the description supplied by the current target.
+
+@cindex show tdesc filename
+@item show tdesc filename
+Show the filename to read for a target description, if any.
+@end table
+
+
+@node Target Description Format
+@section Target Description Format
+@cindex target descriptions, XML format
+
+A target description annex is an @uref{http://www.w3.org/XML/, XML}
+document which complies with the Document Type Definition provided in
+the @value{GDBN} sources in @file{gdb/features/gdb-target.dtd}. This
+means you can use generally available tools like @command{xmllint} to
+check that your feature descriptions are well-formed and valid.
+However, to help people unfamiliar with XML write descriptions for
+their targets, we also describe the grammar here.
+
+Target descriptions can identify the architecture of the remote target
+and (for some architectures) provide information about custom register
+sets. @value{GDBN} can use this information to autoconfigure for your
+target, or to warn you if you connect to an unsupported target.
+
+Here is a simple target description:
+
+@smallexample
+<target version="1.0">
+ <architecture>i386:x86-64</architecture>
+</target>
+@end smallexample
+
+@noindent
+This minimal description only says that the target uses
+the x86-64 architecture.
+
+A target description has the following overall form, with [ ] marking
+optional elements and @dots{} marking repeatable elements. The elements
+are explained further below.
+
+@smallexample
+<?xml version="1.0"?>
+<!DOCTYPE target SYSTEM "gdb-target.dtd">
+<target version="1.0">
+ @r{[}@var{architecture}@r{]}
+ @r{[}@var{feature}@dots{}@r{]}
+</target>
+@end smallexample
+
+@noindent
+The description is generally insensitive to whitespace and line
+breaks, under the usual common-sense rules. The XML version
+declaration and document type declaration can generally be omitted
+(@value{GDBN} does not require them), but specifying them may be
+useful for XML validation tools. The @samp{version} attribute for
+@samp{<target>} may also be omitted, but we recommend
+including it; if future versions of @value{GDBN} use an incompatible
+revision of @file{gdb-target.dtd}, they will detect and report
+the version mismatch.
+
+@subsection Inclusion
+@cindex target descriptions, inclusion
+@cindex XInclude
+@ifnotinfo
+@cindex <xi:include>
+@end ifnotinfo
+
+It can sometimes be valuable to split a target description up into
+several different annexes, either for organizational purposes, or to
+share files between different possible target descriptions. You can
+divide a description into multiple files by replacing any element of
+the target description with an inclusion directive of the form:
+
+@smallexample
+<xi:include href="@var{document}"/>
+@end smallexample
+
+@noindent
+When @value{GDBN} encounters an element of this form, it will retrieve
+the named XML @var{document}, and replace the inclusion directive with
+the contents of that document. If the current description was read
+using @samp{qXfer}, then so will be the included document;
+@var{document} will be interpreted as the name of an annex. If the
+current description was read from a file, @value{GDBN} will look for
+@var{document} as a file in the same directory where it found the
+original description.
+
+@subsection Architecture
+@cindex <architecture>
+
+An @samp{<architecture>} element has this form:
+
+@smallexample
+ <architecture>@var{arch}</architecture>
+@end smallexample
+
+@var{arch} is an architecture name from the same selection
+accepted by @code{set architecture} (@pxref{Targets, ,Specifying a
+Debugging Target}).
+
+@subsection Features
+@cindex <feature>
+
+Each @samp{<feature>} describes some logical portion of the target
+system. Features are currently used to describe available CPU
+registers and the types of their contents. A @samp{<feature>} element
+has this form:
+
+@smallexample
+<feature name="@var{name}">
+ @r{[}@var{type}@dots{}@r{]}
+ @var{reg}@dots{}
+</feature>
+@end smallexample
+
+@noindent
+Each feature's name should be unique within the description. The name
+of a feature does not matter unless @value{GDBN} has some special
+knowledge of the contents of that feature; if it does, the feature
+should have its standard name. @xref{Standard Target Features}.
+
+@subsection Types
+
+Any register's value is a collection of bits which @value{GDBN} must
+interpret. The default interpretation is a two's complement integer,
+but other types can be requested by name in the register description.
+Some predefined types are provided by @value{GDBN} (@pxref{Predefined
+Target Types}), and the description can define additional composite types.
+
+Each type element must have an @samp{id} attribute, which gives
+a unique (within the containing @samp{<feature>}) name to the type.
+Types must be defined before they are used.
+
+@cindex <vector>
+Some targets offer vector registers, which can be treated as arrays
+of scalar elements. These types are written as @samp{<vector>} elements,
+specifying the array element type, @var{type}, and the number of elements,
+@var{count}:
+
+@smallexample
+<vector id="@var{id}" type="@var{type}" count="@var{count}"/>
+@end smallexample
+
+@cindex <union>
+If a register's value is usefully viewed in multiple ways, define it
+with a union type containing the useful representations. The
+@samp{<union>} element contains one or more @samp{<field>} elements,
+each of which has a @var{name} and a @var{type}:
+
+@smallexample
+<union id="@var{id}">
+ <field name="@var{name}" type="@var{type}"/>
+ @dots{}
+</union>
+@end smallexample
+
+@subsection Registers
+@cindex <reg>
+
+Each register is represented as an element with this form:
+
+@smallexample
+<reg name="@var{name}"
+ bitsize="@var{size}"
+ @r{[}regnum="@var{num}"@r{]}
+ @r{[}save-restore="@var{save-restore}"@r{]}
+ @r{[}type="@var{type}"@r{]}
+ @r{[}group="@var{group}"@r{]}/>
+@end smallexample
+
+@noindent
+The components are as follows:
+
+@table @var
+
+@item name
+The register's name; it must be unique within the target description.
+
+@item bitsize
+The register's size, in bits.
+
+@item regnum
+The register's number. If omitted, a register's number is one greater
+than that of the previous register (either in the current feature or in
+a preceeding feature); the first register in the target description
+defaults to zero. This register number is used to read or write
+the register; e.g.@: it is used in the remote @code{p} and @code{P}
+packets, and registers appear in the @code{g} and @code{G} packets
+in order of increasing register number.
+
+@item save-restore
+Whether the register should be preserved across inferior function
+calls; this must be either @code{yes} or @code{no}. The default is
+@code{yes}, which is appropriate for most registers except for
+some system control registers; this is not related to the target's
+ABI.
+
+@item type
+The type of the register. @var{type} may be a predefined type, a type
+defined in the current feature, or one of the special types @code{int}
+and @code{float}. @code{int} is an integer type of the correct size
+for @var{bitsize}, and @code{float} is a floating point type (in the
+architecture's normal floating point format) of the correct size for
+@var{bitsize}. The default is @code{int}.
+
+@item group
+The register group to which this register belongs. @var{group} must
+be either @code{general}, @code{float}, or @code{vector}. If no
+@var{group} is specified, @value{GDBN} will not display the register
+in @code{info registers}.
+
+@end table
+
+@node Predefined Target Types
+@section Predefined Target Types
+@cindex target descriptions, predefined types
+
+Type definitions in the self-description can build up composite types
+from basic building blocks, but can not define fundamental types. Instead,
+standard identifiers are provided by @value{GDBN} for the fundamental
+types. The currently supported types are:
+
+@table @code
+
+@item int8
+@itemx int16
+@itemx int32
+@itemx int64
+Signed integer types holding the specified number of bits.
+
+@item uint8
+@itemx uint16
+@itemx uint32
+@itemx uint64
+Unsigned integer types holding the specified number of bits.
+
+@item code_ptr
+@itemx data_ptr
+Pointers to unspecified code and data. The program counter and
+any dedicated return address register may be marked as code
+pointers; printing a code pointer converts it into a symbolic
+address. The stack pointer and any dedicated address registers
+may be marked as data pointers.
+
+@item ieee_single
+Single precision IEEE floating point.
+
+@item ieee_double
+Double precision IEEE floating point.
+
+@item arm_fpa_ext
+The 12-byte extended precision format used by ARM FPA registers.
+
+@end table
+
+@node Standard Target Features
+@section Standard Target Features
+@cindex target descriptions, standard features
+
+A target description must contain either no registers or all the
+target's registers. If the description contains no registers, then
+@value{GDBN} will assume a default register layout, selected based on
+the architecture. If the description contains any registers, the
+default layout will not be used; the standard registers must be
+described in the target description, in such a way that @value{GDBN}
+can recognize them.
+
+This is accomplished by giving specific names to feature elements
+which contain standard registers. @value{GDBN} will look for features
+with those names and verify that they contain the expected registers;
+if any known feature is missing required registers, or if any required
+feature is missing, @value{GDBN} will reject the target
+description. You can add additional registers to any of the
+standard features --- @value{GDBN} will display them just as if
+they were added to an unrecognized feature.
+
+This section lists the known features and their expected contents.
+Sample XML documents for these features are included in the
+@value{GDBN} source tree, in the directory @file{gdb/features}.
+
+Names recognized by @value{GDBN} should include the name of the
+company or organization which selected the name, and the overall
+architecture to which the feature applies; so e.g.@: the feature
+containing ARM core registers is named @samp{org.gnu.gdb.arm.core}.
+
+The names of registers are not case sensitive for the purpose
+of recognizing standard features, but @value{GDBN} will only display
+registers using the capitalization used in the description.
+
+@menu
+* ARM Features::
+* M68K Features::
+@end menu
+
+
+@node ARM Features
+@subsection ARM Features
+@cindex target descriptions, ARM features
+
+The @samp{org.gnu.gdb.arm.core} feature is required for ARM targets.
+It should contain registers @samp{r0} through @samp{r13}, @samp{sp},
+@samp{lr}, @samp{pc}, and @samp{cpsr}.
+
+The @samp{org.gnu.gdb.arm.fpa} feature is optional. If present, it
+should contain registers @samp{f0} through @samp{f7} and @samp{fps}.
+
+The @samp{org.gnu.gdb.xscale.iwmmxt} feature is optional. If present,
+it should contain at least registers @samp{wR0} through @samp{wR15} and
+@samp{wCGR0} through @samp{wCGR3}. The @samp{wCID}, @samp{wCon},
+@samp{wCSSF}, and @samp{wCASF} registers are optional.
+
+@subsection MIPS Features
+@cindex target descriptions, MIPS features
+
+The @samp{org.gnu.gdb.mips.cpu} feature is required for MIPS targets.
+It should contain registers @samp{r0} through @samp{r31}, @samp{lo},
+@samp{hi}, and @samp{pc}. They may be 32-bit or 64-bit depending
+on the target.
+
+The @samp{org.gnu.gdb.mips.cp0} feature is also required. It should
+contain at least the @samp{status}, @samp{badvaddr}, and @samp{cause}
+registers. They may be 32-bit or 64-bit depending on the target.
+
+The @samp{org.gnu.gdb.mips.fpu} feature is currently required, though
+it may be optional in a future version of @value{GDBN}. It should
+contain registers @samp{f0} through @samp{f31}, @samp{fcsr}, and
+@samp{fir}. They may be 32-bit or 64-bit depending on the target.
+
+The @samp{org.gnu.gdb.mips.linux} feature is optional. It should
+contain a single register, @samp{restart}, which is used by the
+Linux kernel to control restartable syscalls.
+
+@node M68K Features
+@subsection M68K Features
+@cindex target descriptions, M68K features
+
+@table @code
+@item @samp{org.gnu.gdb.m68k.core}
+@itemx @samp{org.gnu.gdb.coldfire.core}
+@itemx @samp{org.gnu.gdb.fido.core}
+One of those features must be always present.
+The feature that is present determines which flavor of m86k is
+used. The feature that is present should contain registers
+@samp{d0} through @samp{d7}, @samp{a0} through @samp{a5}, @samp{fp},
+@samp{sp}, @samp{ps} and @samp{pc}.
+
+@item @samp{org.gnu.gdb.coldfire.fp}
+This feature is optional. If present, it should contain registers
+@samp{fp0} through @samp{fp7}, @samp{fpcontrol}, @samp{fpstatus} and
+@samp{fpiaddr}.
+@end table
+
@include gpl.texi
@raisesections
projects / deliverable / binutils-gdb.git / blobdiff